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http断点续传简单实现(java)

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/* g` kZ T} h  
**SiteFileFetch.java ~W/}:;  
*/ >VypE8H]x  
package NetFox; <M`-`v6H  
import java.io.*; ;HT0w_,  
import java.net.*; w=gQ3j#s  
o8mo=V4j  
|/2LWc?  
public class SiteFileFetch extends Thread { }7&\eV{qU  
+%x^RV}  
=>.DD<g"  
SiteInfoBean siteInfoBean = null; //文件信息Bean \4C)~T:*  
long[] nStartPos; //开始位置 Fv;u1Atiw  
long[] nEndPos; //结束位置 wbl ${@4  
FileSplitterFetch[] fileSplitterFetch; //子线程对象 h FDze  
long nFileLength; //文件长度 r \9:<i8  
boolean bFirst = true; //是否第一次取文件 @],Z 2  
boolean bStop = false; //停止标志  s"#CkG  
File tmpFile; //文件下载的临时信息 -wBnwn-  
DataOutputStream output; //输出到文件的输出流 *j/ uihY  
YlG; A\]k  
//负责整个文件的抓取,控制内部线程(FileSplitterFetch类) _y|[Z;  
public SiteFileFetch(SiteInfoBean bean) throws IOException M2a}x+5'  
{ [6oq##  
siteInfoBean = bean; b,z R5R^D;  
//tmpFile = File.createTempFile ("zhong","1111",new File(bean.getSFilePath())); R<_mK33hd  
tmpFile = new File(bean.getSFilePath()+File.separator + bean.getSFileName()+".info"); pFS F[9?e>  
if(tmpFile.exists ()) @_G` Ok4  
{ fdg[{T4:  
bFirst = false; `9]P/J^  
read_nPos(); 5ZZd.9ZgM  
} r .{rNR  
else NEZH<#  
{ 32TP Mk  
nStartPos = new long[bean.getNSplitter()]; U[blq M  
nEndPos = new long[bean.getNSplitter()]; 1 VPg`+o  
} b;SFI^  
X9p+a,  
ojiM2QT}m  
3`mC"a b /  
} +k# mvPq  
Y=PzN3  
i%#th'C!P  
public void run() QxP` fKC8  
{ hQ\#Fhu7  
//获得文件长度 Rs`Vr_?Hk  
//分割文件 ~oEXM ?M  
//实例FileSplitterFetch n5/ZJur  
//启动FileSplitterFetch线程 hnH)Jy;>  
//等待子线程返回 ,^UcRZ8.H  
try{ bkJwPs  
if(bFirst) /5Gnb.zN)  
{ l#mqV@?A~  
nFileLength = getFileSize(); >\N$>"~a  
if(nFileLength == -1) d@_'P`%-  
{ *Cc$eR]-  
System.err.println("File Length is not known!"); I^6c 0`  
} /&y,vkZTT  
else if(nFileLength == -2) 5%vP~vy_}  
{ O~7p^i}  
System.err.println("File is not access!"); !pE>O-| K  
} }W^V^i)  
else tyBg7dP  
{ Lh8# I&x  
for(int i=0;i<nStartPos.length;i++) e7)>U!9c9  
{ C.DoXE7  
nStartPos = (long)(i*(nFileLength/nStartPos.length)); %D%e:se  
} 1\"BvFE*E~  
for(int i=0;i<nEndPos.length-1;i++) P}w^9=;S  
{ d!a2[2Us  
nEndPos = nStartPos[i+1]; ]~4}(\u  
} A5(kOtgiT  
nEndPos[nEndPos.length-1] = nFileLength; ?j},O=JFn  
} ?STI8AdO  
} <"j"h=tm}  
^MF=,U'8  
&q"uy:Rd  
//启动子线程 [qc6Q:  
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; 2/a04qA#  
for(int i=0;i<nStartPos.length;i++) z. Ve#~\  
{ ;NvhL|R  
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), :6HiP&<  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), =}6Z{}(TT  
nStartPos,nEndPos,i); kiBOyC!r6  
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); (RI>aDG RH  
fileSplitterFetch.start(); Mz% d_  
} qrORP3D@  
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), w|3fioLs  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); 7ZR0M&pX  
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", bN<O<x1j  
nEndPos = " + nFileLength); n^I|}u\  
// fileSplitterFetch[nPos.length-1].start(); o9(#KC?3  
E(L^hZMc  
fitK2d   
//等待子线程结束 QvyUd%e'5A  
//int count = 0; g*\v}6 h  
//是否结束while循环 dnhpWV hn  
boolean breakWhile = false; QjT#GvHY  
 T!O3(  
_s=Pk[e  
while(!bStop) kB!M[[t  
{ @b(gjOE  
write_nPos(); LqH?3):  
Utility.sleep(500); Qr xO erp  
breakWhile = true; p%i .(A  
>LRaIU>  
p-ii($~ }  
for(int i=0;i<nStartPos.length;i++) 2{Lc^6i(t  
{ qoyGs}/I8  
if(!fileSplitterFetch.bDownOver) zv3<i (  
{ kA->xjk  
breakWhile = false; ;Ef)7GE@\[  
break; ,YuWz$aF{  
} FnU{C=P  
} _{@}Fd?o  
if(breakWhile) ^9m^#"ZW`  
break; #v]aT  ]}  
l.LFlwt  
YfYL?G  
//count++; ~(L<uFU V  
//if(count>4) -_H2FlB  
// siteStop(); .<|4PG  
} -2m Ogv  
$DMu~wwfG  
3  %{'Uh,  
System.err.println("文件下载结束!"); fn"jYSy  
} ?&t|?@  
catch(Exception e){e.printStackTrace ();} SGT-B.  
} mfi'>o#  
Zm'::+ tl  
c`[uQXv  
//获得文件长度 pJ@DHj2@  
public long getFileSize() &-. eu  
{ 3t}o0Ai9  
int nFileLength = -1; 1x5CsmS  
try{ )6S}O* 1  
URL url = new URL(siteInfoBean.getSSiteURL()); .J! $,O@  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); YuZ   
httpConnection.setRequestProperty("User-Agent","NetFox"); ROiX =i  
"VOW V3Z  
p!5JO4F$  
int responseCode=httpConnection.getResponseCode(); _ O71r}4  
if(responseCode>=400) Hw-oh?=  
{ IF21T  
processErrorCode(responseCode); Yoym5<xE  
return -2; //-2 represent access is error ?z36mj"`o  
} XzwQ,+IAr  
^)K[1]"uM  
@9Pn(fd]  
String sHeader; x@(f^P  
%>}7 $Y%  
|gxB; GG  
for(int i=1;;i++) 761"S@tf$}  
{ 4BL,/(W] x  
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); ]3cf}Au  
//Utility.log(in.readLine()); [~%;E[ky$  
sHeader=httpConnection.getHeaderFieldKey(i); *j;r|P;g  
if(sHeader!=null) * =N 6_  
{ oN}j<6s  
if(sHeader.equals("Content-Length")) -2~ yc2:>A  
{ dD2e"OIX  
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); .j@n6RyN  
break; Ljs(<Gm)-  
} OehB"[;+  
} ^bw~$*"j#  
else H[yLl v  
break; -m-WUox4"  
} S6:gow(wU  
} y#W8] <dS"  
catch(IOException e){e.printStackTrace ();} G+yz8@  
catch(Exception e){e.printStackTrace ();} `6F8Kqltr  
AxQ/  
{.)~4.LhQM  
Utility.log(nFileLength); 8+b3u05  
Sk%|-T(d$  
~x\ Q\Cxp  
return nFileLength; &3/H P)*<]  
} AR2+W^aM3  
/{} ]Hu  
l3$?eGGM  
//保存下载信息(文件指针位置) 7oSuLo=  
private void write_nPos() -$p-o Z)  
{ <]`2H}*U'  
try{ mTbPz Z4  
output = new DataOutputStream(new FileOutputStream(tmpFile)); ;]ew>P)  
output.writeInt(nStartPos.length); )[Cm*Xxa$  
for(int i=0;i<nStartPos.length;i++) bhT]zsBK  
{ No+zw%l0E  
// output.writeLong(nPos); PQay sdb  
output.writeLong(fileSplitterFetch.nStartPos); ,4$J|^T&  
output.writeLong(fileSplitterFetch.nEndPos); ~hX'FV  
} =jHy6)6w  
output.close(); "61n?Z#,M[  
} #&gy@!a~  
catch(IOException e){e.printStackTrace ();} 4<HJD&@V  
catch(Exception e){e.printStackTrace ();} K6Ua~N^  
} hY'%SV p  
06O  
/PS]AM  
//读取保存的下载信息(文件指针位置) )Jn80~U|1  
private void read_nPos() o%7yhCY  
{ L0~O6*bk  
try{ +?'acn  
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); YiMecu  
int nCount = input.readInt(); `Nr7N#g+u  
nStartPos = new long[nCount]; 14zzWzKx  
nEndPos = new long[nCount]; l"#,O$x"#@  
for(int i=0;i<nStartPos.length;i++) vnpX-c  
{ 6dlPS{H#U  
nStartPos = input.readLong(); D.f=!rT7E7  
nEndPos = input.readLong(); zt6ep=  
} ('oUcDOFTS  
input.close(); &*SnDuc  
} &GAx*.L  
catch(IOException e){e.printStackTrace ();} E$ rSrT(  
catch(Exception e){e.printStackTrace ();} fba3aId[  
} N<%,3W_-_  
R~([  
a#=-Aj-  
private void processErrorCode(int nErrorCode) 'z:p8"h}  
{ &n wg$z{Y  
System.err.println("Error Code : " + nErrorCode); ;C%EF  
} yFqC-t-i  
Ckp=d  
/;1FZ<zU  
//停止文件下载 $Tza<nA  
public void siteStop() [x,&Gwa  
{ /zKuVaC  
bStop = true; 6iC:l%|u  
for(int i=0;i<nStartPos.length;i++) !NtY4O/  
fileSplitterFetch.splitterStop(); wr(?L7 $+  
kzu=-@s  
c#Bde-dh  
} 5[k35 c{  
} $G[##j2  
//负责部分文件的抓取 -M}iDBJx>#  
**FileSplitterFetch.java mLO6`]p{H  
*/ T rW3@@}j  
package NetFox; I5,Fh>  
FqfeH_-U  
)g9qkQ8q  
import java.io.*; -u{:39y{n  
import java.net.*; ;f\0GsA#  
3 a`-_<  
q6dq@   
public class FileSplitterFetch extends Thread { |rQ;|+.  
4m:E:zVn  
=v8q  
String sURL; //File URL s#ykD{ Z  
long nStartPos; //File Snippet Start Position (0r6_8e6xv  
long nEndPos; //File Snippet End Position ' BpRiN  
int nThreadID; //Thread's ID 2#!D"F  
boolean bDownOver = false; //Downing is over ~JJv 2  
boolean bStop = false; //Stop identical ~ p.23G]x  
FileAccessI fileAccessI = null; //File Access interface -oj@ c OZ  
OB%y'mo7]  
lq~n*uwO}t  
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException N*#SY$!y  
{ bZ)Jgz  
this.sURL = sURL; F`l1I=;  
this.nStartPos = nStart; R0>L[1o  
this.nEndPos = nEnd; 2rk_ ssvs  
nThreadID = id; 4{TUoI6ii  
fileAccessI = new FileAccessI(sName,nStartPos);//定位 (`&g  
} _z;N|Xe  
9ccEF6o0=  
" 1 Bn/Q  
public void run() LS`Gg7]S  
{ y =CemJ[~  
while(nStartPos < nEndPos && !bStop) &^Io\  
{ /T?['#:r-)  
<M=K!k  
:Vg,[\I{  
try{ 2&M 8Wb#  
URL url = new URL(sURL); TUT>*  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); lH[N*9G(  
httpConnection.setRequestProperty("User-Agent","NetFox"); C..O_Zn{g  
String sProperty = "bytes="+nStartPos+"-"; F 1BPzRo`  
httpConnection.setRequestProperty("RANGE",sProperty); :mij%nQ>$  
Utility.log(sProperty); d%<Uh(+:  
6i%)'dl  
I$YF55uB  
InputStream input = httpConnection.getInputStream(); g$ h!:wW  
//logResponseHead(httpConnection); ^;'3(m=  
~o+u:]  
d(tq;2-  
byte[] b = new byte[1024]; 3E#acnqn*  
int nRead; SpkD  
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) GYBM]mW^ W  
{ {_ocW@@  
nStartPos += fileAccessI.write(b,0,nRead); Y!KGJ^.mF  
//if(nThreadID == 1) ^'}Td~(  
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); ~ 60J  
} PpbW+}aCF  
QDU^yVa_  
yY!jkRq%w  
Utility.log("Thread " + nThreadID + " is over!"); {pVD`#Tl[  
bDownOver = true; yCwQ0|  
//nPos = fileAccessI.write (b,0,nRead); I)6)~[:'  
} ^ H'|iju  
catch(Exception e){e.printStackTrace ();} PS>k67sI  
} UXd\Q''  
} SgJQH7N  
bH&[O`vf  
-IPc;`<  
//打印回应的头信息 h5F1mr1Sa  
public void logResponseHead(HttpURLConnection con) sx6` g;  
{ oYu5]ry  
for(int i=1;;i++) I` /'\cU9  
{ UlyX$f%2  
String header=con.getHeaderFieldKey(i); Zf|f $1-  
if(header!=null) gbF.Q7?$u  
//responseHeaders.put(header,httpConnection.getHeaderField(header)); ^NP" m  
Utility.log(header+" : "+con.getHeaderField(header)); sC/T)q2  
else zF{5!b  
break; $L?stgU  
} &0M^UvO  
} U|,VH-#  
)5B90[M|t  
k*M1m'1  
public void splitterStop() Ix"uk6 h  
{ p 3X>  
bStop = true; sURHj&:t|  
} DI+kO(S  
N1_nBQF )  
1h|JKu0  
} \ ddbqg?`  
0?k/vV4  
R7+k=DI  
/* &FGz53fd4  
**FileAccess.java \ B<(9  
*//文件访问(定位,写) k pEES{f  
package NetFox; |FH/Q-7[  
import java.io.*; koe&7\ _@  
RoP z?,u  
-]HO8}-Rjs  
public class FileAccessI implements Serializable{ EY':m_7W  
xj(&EGY:  
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 A:>G:X5t  
RandomAccessFile oSavedFile; ~,.Agx  
long nPos; s>^*GQw  
bc%7-%  
W +C\/  
public FileAccessI() throws IOException Q']:k}y  
{ WC0@g5;1[  
this("",0); 3Cq17A 9  
} UEt #;e  
{V,rWg  
9w(QM-u  
public FileAccessI(String sName,long nPos) throws IOException P6dIU/w  
{ ^<7)w2ns  
oSavedFile = new RandomAccessFile(sName,"rw"); $GPenQ~},  
this.nPos = nPos; (yn!~El3  
oSavedFile.seek(nPos);  ]Ocf %(  
} |v:8^C7  
4, 8gf2  
 jmz, 1[  
public synchronized int write(byte[] b,int nStart,int nLen) J8~3LE )G  
{ ZmUS}   
int n = -1; OiZPL"Q(K  
try{ K'7i$bl%  
oSavedFile.write(b,nStart,nLen); Q];+?Pu.  
n = nLen; ZoF\1C ^  
} K>"M# T  
catch(IOException e) rer=o S  
{ +kmPQdO;*/  
e.printStackTrace (); ^;!A`t  
} x=gZ7$?A  
ts aD5B  
Rq<T2}K  
return n; 48Z{wV,  
} JIQS'r  
%HpTQ   
1B}6 zJ  
} 8(\Az5%  
'cu( Sd}  
&Dgho  
/* -H#{[M8xX  
**SiteInfoBean.java [}N?'foLb  
*/ )UO:J7K  
package NetFox; 3#j%F  
h 1:uTrtA  
HJ:s)As  
public class SiteInfoBean { h)~KD%  
% Lhpj[C  
kzMCI)>"  
private String sSiteURL; //Site's URL %F` c Nw]  
private String sFilePath; //Saved File's Path %e+hM $Q  
private String sFileName; //Saved File's Name =;9Wh!{  
private int nSplitter; //Count of Splited Downloading File 50F6jj  
D: NBb!   
9N:Bu'j&/  
public SiteInfoBean() m1heU3BUWU  
{//nSplitter的缺省值为5 j *Ta?'*  
//default value of nSplitter is 5 f nX!wN  
this("","","",5); F<M#T  
} 7%c9 nY  
U"v(9m@  
k3da*vwE  
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) 2G=Bav\n+  
{ k"uqso/  
sSiteURL= sURL; xa[<k >r3  
sFilePath = sPath; Zz'(!h Uy  
sFileName = sName; b'pbf  
this.nSplitter = nSpiltter; Z2_eTC u  
. p^='Kz?  
/J aH  
} !h4S`2oZ/  
Cg?D<l4  
<UQaRI[55  
public String getSSiteURL() '>^+_|2  
{ -v'7;L0K  
return sSiteURL; 5?r#6:(yI  
} 2asA]sY  
'ejuzE9  
N)K};yMf  
public void setSSiteURL(String value) mT <4@RrB  
{ WO?EzQ ?  
sSiteURL = value; BNw^ _j1  
} >eQ;\j  
1mm/Ssw:C  
QZ$94XLI  
public String getSFilePath() `C%,Nj  
{ UTGR{>=>  
return sFilePath; GNS5v-"H  
} }{[H@uhjH  
{a.{x+!5I-  
~ ' 81  
public void setSFilePath(String value) {mY<R`Ee  
{ V@&zn8?  
sFilePath = value; z9}rT<hy  
} ;{ u{F L  
iT1"Le/N  
!MS z%QcO  
public String getSFileName() .^>[@w3  
{ I& l1b>  
return sFileName; gQ3Co./  
} y8HLrBTza  
C18pK8-  
H=?v$! i  
public void setSFileName(String value) ol^V@3[<  
{ k!H;(B"s-  
sFileName = value; C(Ujx=G+3  
} /tM<ois*  
SL" ;\[uI  
58,_  
public int getNSplitter() `e .;P  
{ M7^PWC  
return nSplitter; hSSF]  
} E]WammX c  
VJJGTkm  
x tg3~/H  
public void setNSplitter(int nCount) '31pb9@fH  
{ rV d(H  
nSplitter = nCount; FiMP_ y*S  
} e;~[PYeu  
} `Jhu&MWg  
YNA %/  
uNZJNrV%  
/* }WS%nQA  
**Utility.java >DVjO9Kf  
*/ 3GUO   
package NetFox; ftq&<8  
!^cQPX2<  
,u^i0uOg  
public class Utility { V9z/yNo  
mV^+`GWvo  
dy N`9  
public Utility() &?YbAo_K  
{ \g< M\3f  
J @C8;]  
V^B'T]s  
} z #c)Q  
<\!+J\YTA  
//线程睡眠 Ug*:o d  
public static void sleep(int nSecond) li;Np5P  
{ !q=ej^(S  
try{ w]X~I/6g  
Thread.sleep(nSecond); wG [X*/v  
} ,2q LiE>  
catch(Exception e) F?&n5R.  
{ }+G6`Zd  
e.printStackTrace (); !:t}8  
} fC+<n{"C  
} y3 @R>@$  
GqBZWmAB  
//日志 Z12-Vps  
public static void log(String sMsg) fiqeXE?E  
{ .vYU4g]  
System.err.println(sMsg); 1.U5gW/3L  
} \E1[ /  
|S[Gg  
vggyQf%  
public static void log(int sMsg) n,}\;Bp  
{ (@@t,\iF  
System.err.println(sMsg); ' _Ij9{M  
} f{MXH&d 1\  
} d|CSWcU  
N-EVH e'}6  
VSP6osX{  
/* Z8$n-0Ww  
**TestMethod.java Mu$9#[/  
*/ CIAHsbn.A  
package NetFox; aal5d_Y  
<|9s {z  
oe`t ? (U  
public class TestMethod { =EwC6+8*M  
p'z fo!  
Lpd q^X  
public TestMethod() ee}&~%  
{ ///xx/weblogic60b2_win.exe }@%A@A{R  
try{ c+$alw L~  
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); It>8XKS  
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); Hh`x>{,|S  
SiteFileFetch fileFetch = new SiteFileFetch(bean); U;f~Q6iu  
fileFetch.start(); :E'uV" j%  
} uLXMEx<^  
catch(Exception e){e.printStackTrace ();} 7\I,;swo  
&?C% -"|c  
60p*$Vqy  
} +I1>; {{  
0Snl_@s  
X:Z4QqT  
public static void main(String[] args) j"o8]UT/  
{ x&>zD0\ :\  
new TestMethod(); sbn|D\p  
} 2VO bj7F  
} x9S~ns+r  
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