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http断点续传简单实现(java)

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/* -} +PE 4fh  
**SiteFileFetch.java ,E4qxZC(X  
*/ E+eC #!&w  
package NetFox; _?>f9K$1  
import java.io.*; cp+eh  
import java.net.*; M]e _@:!  
}$s._)a  
9K{0x7~  
public class SiteFileFetch extends Thread { 23`pog{n  
yy\d<-X~  
6EG`0h6  
SiteInfoBean siteInfoBean = null; //文件信息Bean x 0L,$Ol  
long[] nStartPos; //开始位置  u8[jD^  
long[] nEndPos; //结束位置 {>#4{D00  
FileSplitterFetch[] fileSplitterFetch; //子线程对象 GZ"J6/0-|  
long nFileLength; //文件长度 sT"{ e7;F;  
boolean bFirst = true; //是否第一次取文件 N_E :?Jo  
boolean bStop = false; //停止标志 {7FD-Q[tS  
File tmpFile; //文件下载的临时信息 ~Q 1%DV.  
DataOutputStream output; //输出到文件的输出流 Pe7% 9  
[kZe6gYP&  
//负责整个文件的抓取,控制内部线程(FileSplitterFetch类) }-M% $ ~`  
public SiteFileFetch(SiteInfoBean bean) throws IOException 1Q9e S&  
{ 79MB_Is]s  
siteInfoBean = bean; D5 ^WiQ<  
//tmpFile = File.createTempFile ("zhong","1111",new File(bean.getSFilePath())); %C*h/AW)'  
tmpFile = new File(bean.getSFilePath()+File.separator + bean.getSFileName()+".info"); 9{{CNy p  
if(tmpFile.exists ()) o=do L{ #  
{ &v_b7h  
bFirst = false; {I"d"'h  
read_nPos(); <' b%  
} HoKN<w  
else +JL"Z4b@R}  
{ g ??@~\Ov  
nStartPos = new long[bean.getNSplitter()]; p:^;A/D  
nEndPos = new long[bean.getNSplitter()]; 5nG$6Hw  
} %g%#=a;]q  
Yy8%vDdJO  
jQ Of+ZE  
w1|YR  
} KP!ctlP~  
3`m n#RM  
9Vv&\m!0  
public void run() 8I=migaxP  
{ |;P9S  
//获得文件长度 ?QCHkhU  
//分割文件 Y<-dd"\  
//实例FileSplitterFetch 0@8EIQxK"  
//启动FileSplitterFetch线程 ||k^pzj%  
//等待子线程返回 4 5\%2un  
try{ _zj}i1!E"  
if(bFirst) LP:C9 Ol\  
{ }c*6|B@f  
nFileLength = getFileSize(); F>A&L8  
if(nFileLength == -1) kculHIa\.  
{ |JH1?n  
System.err.println("File Length is not known!"); p)=Fi}#D\  
} ySwvjP7f  
else if(nFileLength == -2) #N"K4@]{  
{ c>RS~/Y  
System.err.println("File is not access!"); ~*h` ?A0  
} h+h`0(z  
else p,+$7f1S  
{ bPtbU :G  
for(int i=0;i<nStartPos.length;i++) QA&BNG  
{ 8z, |N#  
nStartPos = (long)(i*(nFileLength/nStartPos.length)); ?yt"  
} mam2]St"  
for(int i=0;i<nEndPos.length-1;i++) "J%/xj  
{ 3EKqXXzOB  
nEndPos = nStartPos[i+1]; 38T2IN  
} c B9`U4<  
nEndPos[nEndPos.length-1] = nFileLength; YkLEK|d  
} O)!MWmr  
} Ym*Ed[S  
u%=M4|7  
rTjV/~  
//启动子线程 G#;$;  
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; ZO $}m?  
for(int i=0;i<nStartPos.length;i++) t`X-jr)g  
{ lvz&7Zb  
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 7:t *&$  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), e'uI~%$NJL  
nStartPos,nEndPos,i); ?gMxGH:B.&  
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); v='h  
fileSplitterFetch.start(); 4#m"t?6!  
} ;F;`y),  
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), \^+=vO;A  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); )5U&^tJ  
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", T=w5FT  
nEndPos = " + nFileLength); EV 8}C=  
// fileSplitterFetch[nPos.length-1].start(); D-BWgK  
^w XXx=Xf  
)Aky:kM$  
//等待子线程结束 L{\au5-4  
//int count = 0; jnuovM!x~  
//是否结束while循环 6A]Ia4PL  
boolean breakWhile = false; :8bz+3p  
sCFqz[I  
8L<GAe  
while(!bStop) zl j%v/9  
{ it~>)_7*P  
write_nPos(); `}^_>  
Utility.sleep(500); 9ci=]C5o3K  
breakWhile = true; "$tP>PO{<  
L;0ZB=3n  
X|F([,o  
for(int i=0;i<nStartPos.length;i++) 'o2x7~C@  
{ bqxbOQd  
if(!fileSplitterFetch.bDownOver) p`3pRrER  
{ }w&+ H28.#  
breakWhile = false; el*C8TWlw  
break; 37@_"  
} Q2)z1'Wv  
} i!30f^9D-S  
if(breakWhile) :*"0o{ ie  
break; A({8p  
nJ`JF5tI  
&z r..i4O  
//count++; UNJ]$x0  
//if(count>4) x62 b=k}  
// siteStop(); MeqW/!72$L  
} Fa$ pr`  
qsUlfv9L6  
eXI^9uH  
System.err.println("文件下载结束!"); 2c.~cNx`q[  
} HPGi5rU  
catch(Exception e){e.printStackTrace ();} XTD _q  
} )x-iru A:  
BOLG#}sm  
MmBM\Dnv  
//获得文件长度 ?3"bu$@8  
public long getFileSize() N&!qu r \  
{ [{ak&{R,9{  
int nFileLength = -1; :cmfy6h]  
try{ is%qG?,P  
URL url = new URL(siteInfoBean.getSSiteURL()); +%G*)8N3  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); *K6 V$_{S  
httpConnection.setRequestProperty("User-Agent","NetFox"); C G~ )`  
 ] }XK  
?]081l7cd  
int responseCode=httpConnection.getResponseCode(); cjf}yn  
if(responseCode>=400) #_}lF<k  
{ ,>n 4 `A  
processErrorCode(responseCode); -Rhxib|<  
return -2; //-2 represent access is error xQC.ap  
} twqjaFA>  
+d6/*}ht  
ul+ +h4N  
String sHeader; &E$jAqc  
IBY3QG  
%b2.JGBqJ  
for(int i=1;;i++) '2a}1?  
{ FS r`Y  
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); Xi_>hL+R(  
//Utility.log(in.readLine()); Zr_{Z@IpU  
sHeader=httpConnection.getHeaderFieldKey(i); pJ x88LfR  
if(sHeader!=null) \BaN?u)a  
{ '|<+QAc  
if(sHeader.equals("Content-Length")) |C@)#.nm[  
{ ho2o/>Ef3  
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); Z.$ncP0s  
break; %O;"Z`I  
} \pB"R$YZ6  
}  GWgjbp  
else LWc}j`Wd  
break; oYnA 3  
} Aj.TX%}`h  
} 8zGe5Dn9  
catch(IOException e){e.printStackTrace ();} EXg\a#4['  
catch(Exception e){e.printStackTrace ();} X%xX3e'  
; )O)\__"-  
B=#rp*vwL  
Utility.log(nFileLength); X3I\O,"I  
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Eu\&}n`i  
return nFileLength; @#1k+tSA,  
} )H#Hs<)Qy  
f .rz2)o  
;RW!l pGjP  
//保存下载信息(文件指针位置) Mi9A%ZmP  
private void write_nPos() bV&/)eqv  
{ (F]f{8  
try{ /s(/6~D|  
output = new DataOutputStream(new FileOutputStream(tmpFile)); ox] LlRK  
output.writeInt(nStartPos.length); |uQJMf[L)  
for(int i=0;i<nStartPos.length;i++) qr$=oCqa  
{ Yva^JB  
// output.writeLong(nPos); 3'O+  
output.writeLong(fileSplitterFetch.nStartPos); 5[esW  
output.writeLong(fileSplitterFetch.nEndPos); !zwn Fdp  
} m;lwMrY\7>  
output.close(); U;:>vi3p  
} 07Yh  
catch(IOException e){e.printStackTrace ();} |]HU$Gt S  
catch(Exception e){e.printStackTrace ();} |:`f#H  
} BKIAc6  
x SF#ys4v  
eP|:b &  
//读取保存的下载信息(文件指针位置) FD*`$.e3\  
private void read_nPos() >IC.Zt@  
{ *j2P#et  
try{ EYd`qk 3  
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); +?[TH?2c+  
int nCount = input.readInt(); xaX3<V@S  
nStartPos = new long[nCount];  $.(%7[  
nEndPos = new long[nCount]; }]N7CWy  
for(int i=0;i<nStartPos.length;i++) 7qV_QZ!.  
{ bqN({p&  
nStartPos = input.readLong(); xIf,1g@Cq9  
nEndPos = input.readLong(); 1[C,*\X8v  
} Z_D8}$!  
input.close(); ~K 8eRT  
} .JZoZ.FAb  
catch(IOException e){e.printStackTrace ();} %+i g7a:  
catch(Exception e){e.printStackTrace ();} ..3TB=Z#  
} #IA[erf:  
CtV$lXxup  
NwoBM6 #  
private void processErrorCode(int nErrorCode) ++F #Z(p  
{ 7m{ 'V`F  
System.err.println("Error Code : " + nErrorCode); 2[LT!TT  
} [#$-kd~  
"3LOL/7f  
Xz4!#,z/  
//停止文件下载 W*e6F?G  
public void siteStop() ooref orr  
{ U")~bU  
bStop = true; N?U;G*G  
for(int i=0;i<nStartPos.length;i++) 4~hd{8  
fileSplitterFetch.splitterStop(); D)8&v` L S  
a9mLPP  
I1BVqIt1i  
} NZ/gp"D?  
} YTpSR~!Rj  
//负责部分文件的抓取 G$}\~dD  
**FileSplitterFetch.java JGX E{FT  
*/ _W/s=pCh  
package NetFox; f ySzZ  
hf^,  
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import java.io.*; m ,,-rC  
import java.net.*; |3/=dG  
YH&`+ +  
f%` =>l  
public class FileSplitterFetch extends Thread { b/5?)!I  
j1*'yvGM  
kq8:h  
String sURL; //File URL $IA(QC_]AO  
long nStartPos; //File Snippet Start Position Oj\lg2Ck  
long nEndPos; //File Snippet End Position HhhN8t  
int nThreadID; //Thread's ID D'ZR>@w@  
boolean bDownOver = false; //Downing is over hU3c;6]3  
boolean bStop = false; //Stop identical L&MR%5  
FileAccessI fileAccessI = null; //File Access interface WW\u}z.QJ  
=LDzZ:' X  
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public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException [U]U *x  
{ \Pi\c~)Pr  
this.sURL = sURL; 9Iq[@v  
this.nStartPos = nStart; *r@7:a5  
this.nEndPos = nEnd; b4ZZyw  
nThreadID = id; QxH%4 )?  
fileAccessI = new FileAccessI(sName,nStartPos);//定位 R22YKXU  
} 7/a[;`i*!  
S3EY9:^ C  
_?M34&.X  
public void run() tisSj?+  
{ P{i\x#  
while(nStartPos < nEndPos && !bStop) M' e<\wqm  
{ m.pB]yq&  
jB!p,fqcb  
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try{ ~ P"@^cq  
URL url = new URL(sURL); 6O bB/*h  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); u\ro9l  
httpConnection.setRequestProperty("User-Agent","NetFox"); $~!%Px)  
String sProperty = "bytes="+nStartPos+"-"; R2vT\ 6xv  
httpConnection.setRequestProperty("RANGE",sProperty); BCYTlxC'  
Utility.log(sProperty); %i{Z@  
U<gM gA  
@)1>ba  
InputStream input = httpConnection.getInputStream(); zflfV!vAg  
//logResponseHead(httpConnection); Gole7I  
&l"/G%W  
jzI70+E  
byte[] b = new byte[1024]; >!848J  
int nRead; rn $a)^!  
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) 7DDd 1"jE  
{ ?;zu>4f|  
nStartPos += fileAccessI.write(b,0,nRead); a\>+!Vq  
//if(nThreadID == 1) n/6#rj^$  
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); NY 756B*  
} Atc9[<~WG  
 <K;  
C]414Ibi  
Utility.log("Thread " + nThreadID + " is over!"); %V71W3>6WS  
bDownOver = true; !TvNT}4Z  
//nPos = fileAccessI.write (b,0,nRead); FM;NA{  
} _8A  
catch(Exception e){e.printStackTrace ();} g"ha1<y<  
} r*HbglB  
} #%N v\ g;  
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cWjb149@)  
//打印回应的头信息 0gO_dyB  
public void logResponseHead(HttpURLConnection con) mivb}cKM  
{ <}t~^E,  
for(int i=1;;i++) 3 9to5 s,  
{ "5 ;fuM1  
String header=con.getHeaderFieldKey(i); U;`C%vHff  
if(header!=null) J|,Uu^7`  
//responseHeaders.put(header,httpConnection.getHeaderField(header)); V[ju7\>$Z  
Utility.log(header+" : "+con.getHeaderField(header)); 86Hg?!<i.  
else uP, iGA  
break; })W9=xO~  
} <|Srbs+  
} 7]W6\Z  
(rqc_ZU5  
7OAM  
public void splitterStop() 'L?e)u.  
{ fh_+M"Y0`  
bStop = true; -!;2?6R9{  
} ;\j7jz^uC  
zU7co.G  
Ha~F&H|"O  
} _D~l2M  
K&ZN!VN/p  
} I>68dS[  
/* !C\$=\$  
**FileAccess.java 9d&@;&al  
*//文件访问(定位,写) ^POHQQ  
package NetFox; V%h,JA  
import java.io.*; p0*qv"lA  
2[|52+zhc  
`#HtVI  
public class FileAccessI implements Serializable{ +t*V7nW  
j9gn7LS  
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 i(T[  
RandomAccessFile oSavedFile; `-t8ag 3  
long nPos; !LI6_Oq  
JfD-CoQS'  
fg$#ZCi  
public FileAccessI() throws IOException fi%)520  
{ &1 /OwTI4J  
this("",0); WC0z'N({W  
} Kb X&E0  
-t]3 gCLb  
lXtsnQOOK  
public FileAccessI(String sName,long nPos) throws IOException riR(CJ}Ff  
{ LMKhtOZ?  
oSavedFile = new RandomAccessFile(sName,"rw"); $UNC0 (4  
this.nPos = nPos; m tU{d^B  
oSavedFile.seek(nPos); {zX]4 1T  
} Fn>KdoByN  
)<Fq}Q86  
4)"S /u  
public synchronized int write(byte[] b,int nStart,int nLen) dG&^M ".(  
{ >{6U1ft):  
int n = -1; UQZl:DYa  
try{ [Ef6@  
oSavedFile.write(b,nStart,nLen); QB uX#bDV  
n = nLen; 5(zdM)Y7  
} Q XSS  
catch(IOException e) |I[/Fl:  
{ "; 1@f"kw  
e.printStackTrace (); P~ : N  
} d1P|v( `S9  
Qb%o%z?hee  
(+yH   
return n; 3r VfBz  
} (E;+E\E  
Ez8k.]qu  
*+OS;R1<  
} uMx6:   
!"2S'oQKS  
OZc4 -5  
/* }y%c.  
**SiteInfoBean.java CvHE7H|-{  
*/ fmq''1u  
package NetFox; K| dI'TnW  
44NM of8N  
Gv[s86AP,  
public class SiteInfoBean { 1=Z!ZY}}e  
3Ccy %;  
InI>So%e|<  
private String sSiteURL; //Site's URL 3v@h&7<E  
private String sFilePath; //Saved File's Path }u9#S  
private String sFileName; //Saved File's Name ?g\emhG  
private int nSplitter; //Count of Splited Downloading File Nq9\2p  
m"@o  
 nU4to  
public SiteInfoBean() 3k3 C\Cw  
{//nSplitter的缺省值为5 xa.tH)R  
//default value of nSplitter is 5 Ul_ 5"3ze  
this("","","",5); #M%K82"  
}  TZ63=m  
JM1O7I  
V408u y-M  
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) :8K}e]!c1  
{ ?K+q~DzNSD  
sSiteURL= sURL; ~NZL~p  
sFilePath = sPath; ;j.-6#n  
sFileName = sName; F\, vIS  
this.nSplitter = nSpiltter; [~PR\qm  
Ur]/kij  
o%bf7)~s  
} |1GOm=GNK  
6Df*wi!jI  
,<N{Y[n]e  
public String getSSiteURL() HfZ^ED"}  
{ 0 N"N$f  
return sSiteURL; 'W,*mfB  
} IyI0|&r2A  
q{&\nCy  
0-~s0R89A  
public void setSSiteURL(String value) =A!r ZG  
{ ta6>St7.  
sSiteURL = value; l\F71pwSI  
} V@ g v  
[YP{%1*RM  
[GPCd@  
public String getSFilePath() y XKddD  
{ s`ZP2"`f  
return sFilePath; $*VZa3B\  
} 06O_!"GD}  
|h }4J  
\-pqqSy  
public void setSFilePath(String value) 3dSb!q0&N  
{ ,]:Gn5~  
sFilePath = value; ~`Rar2%B  
} ?JG^GD7D  
D2g/P8.<A  
d<+hQ\BF,  
public String getSFileName() GGnlkp& E  
{ /o%VjP"<  
return sFileName; obE8iG@H  
} }zks@7kf  
Unv'm5/L  
L2+cVR  
public void setSFileName(String value) y>.t[*zT  
{ ;DSH$'1i  
sFileName = value; aZ$5"  
} Y0.'u{J*  
S2DG=hi`GK  
67hfve  
public int getNSplitter() gROK4'j6y  
{ 0^R, d M  
return nSplitter; zz[fkH3  
} % YK xdp  
ywl=@  
#bBh. ^  
public void setNSplitter(int nCount) UOsK(mB  
{ #M{qMJHDo  
nSplitter = nCount; ,#FP]$FK  
} gyD;kn\CP  
} i(pHJP:a:  
2,dWD<h  
T\n6^@.>  
/* E_En"r)y  
**Utility.java S :8  
*/ 70GBf"  
package NetFox; 'AX5V-t  
8 eK8-R$  
$&&E[JY  
public class Utility { 2mn AL#  
^P^%Q)QXl  
e*qGrg(E  
public Utility() M,S'4Sz uk  
{ $%q=tn'EX  
nX 9]dz  
(5 @H  
} w6Nn x5Ay  
y/y~<-|<@  
//线程睡眠 qx b]UV,R  
public static void sleep(int nSecond) oWL_Hh%-f`  
{ u1L^INo/  
try{ }rI:pp^KS  
Thread.sleep(nSecond); p09p/  
} 'Gqv`rq&  
catch(Exception e) ;RJ 8h x  
{ 7dcR@v`c  
e.printStackTrace (); 3PGAUQR#"q  
} _<LL@IX  
} @U18Dj[  
A $gn{ c  
//日志 8'zZVX D<  
public static void log(String sMsg) y7M{L8{0  
{ z,4mg6gt  
System.err.println(sMsg); ' {UKO7   
} ] re=8s6  
E#!!tH`lgg  
Cp(2]Eb  
public static void log(int sMsg) Nw'03Jzx_  
{ '"fJA/O  
System.err.println(sMsg); q6)fP4MQ]  
} kFwFPK%B  
} E{&MmrlL,  
.a]#AFX  
-1,0hmn=+  
/* /V:9*C  
**TestMethod.java [K.1 X=O}  
*/ Q}|K29Y:p  
package NetFox; 3y6\0|{1  
8rH6L:]S  
8{!d'Pks  
public class TestMethod { 3{$7tck,  
N o6!gZ1  
d]] z )  
public TestMethod() ![^pAEgx  
{ ///xx/weblogic60b2_win.exe YND}P9 h  
try{ )Q'E^[Ua  
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); g w([08  
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); NC%hsg^0/  
SiteFileFetch fileFetch = new SiteFileFetch(bean); 4}h}`KZZ  
fileFetch.start(); yl~_~<s6  
} WJOoDS!i  
catch(Exception e){e.printStackTrace ();} (MI>7| ';  
\4q|Qno8  
qK a}O*  
} GYfOwV!zB  
80*hi)ux[  
b& +zAt.  
public static void main(String[] args) \~l_w ,Poo  
{ `SFeln{1B  
new TestMethod(); <ToBVG X  
} Lj3o-@\*j  
} hc3hU   
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