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http断点续传简单实现(java)

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/* U< <XeSp  
**SiteFileFetch.java ZP '0=  
*/ m}6Jdt'|  
package NetFox; -`UOqjb]3  
import java.io.*; "v/Yw'! )  
import java.net.*; P|t2%:_  
o+Fm+5t;  
Ako]34Rl,  
public class SiteFileFetch extends Thread { IYv.~IQO  
CV)K=Br5&_  
a9NIK/9  
SiteInfoBean siteInfoBean = null; //文件信息Bean "EwzuM8 f  
long[] nStartPos; //开始位置 8J:=@X^}  
long[] nEndPos; //结束位置 % _nmv  
FileSplitterFetch[] fileSplitterFetch; //子线程对象 D~n-;T  
long nFileLength; //文件长度 d .%2QkL  
boolean bFirst = true; //是否第一次取文件 Yz#E0aTTA  
boolean bStop = false; //停止标志 _ Y7 Um  
File tmpFile; //文件下载的临时信息 g)7@EU2  
DataOutputStream output; //输出到文件的输出流 X0]{8v%  
~ +h4i'  
//负责整个文件的抓取,控制内部线程(FileSplitterFetch类) G|u)eW  
public SiteFileFetch(SiteInfoBean bean) throws IOException wsB  
{ .q1y)l-^Z  
siteInfoBean = bean; %<fs \J^k  
//tmpFile = File.createTempFile ("zhong","1111",new File(bean.getSFilePath())); >R5A@0@d5  
tmpFile = new File(bean.getSFilePath()+File.separator + bean.getSFileName()+".info"); 8Oz9 UcG  
if(tmpFile.exists ()) 6Ta+f3V   
{ <<R2 X1  
bFirst = false; w|abaMam  
read_nPos(); 7^tYtMm|U  
} YdyTt5-  
else S0M i  
{ 0#4A0[vV  
nStartPos = new long[bean.getNSplitter()];  \>||  
nEndPos = new long[bean.getNSplitter()]; 2_}oOt?qiM  
} 3)I]bui  
@saK:z  
@WNqD*)1  
~tn$AtK  
} 2MmHO2  
f3S 8~!  
ubRhJ~XB  
public void run() (2UA,  
{ }B_?7+  
//获得文件长度 70 Ph^e)  
//分割文件 r6GXmr  
//实例FileSplitterFetch 6\k~q.U@XI  
//启动FileSplitterFetch线程 X,bhX/h  
//等待子线程返回 Lp/'-Y_  
try{ !{fu(E  
if(bFirst) c\/-*OYr<  
{ _>ZC;+c?  
nFileLength = getFileSize(); suE8"v!sk  
if(nFileLength == -1) [5ncBY*A7  
{ uQ|LkL%< ^  
System.err.println("File Length is not known!"); 4ETHaIiWp  
} TU': Rt  
else if(nFileLength == -2) {{?MO{Mh*  
{ |=07n K2  
System.err.println("File is not access!"); bR,Es~n  
} "U+c`V=w  
else (<rE1w2s:  
{ ug.|ag'R  
for(int i=0;i<nStartPos.length;i++) }ice*3'3  
{ $B7c\MR j  
nStartPos = (long)(i*(nFileLength/nStartPos.length)); .)=*Yr M  
} <B>hvuCoH  
for(int i=0;i<nEndPos.length-1;i++) pU'${Z~b  
{ M?DZShkV_  
nEndPos = nStartPos[i+1]; EV-sEl8ki  
} _>BYUPY  
nEndPos[nEndPos.length-1] = nFileLength; bDudETl  
} v(GnG  
} QO0@Ax\b  
||fw!8E  
yYSmmgrX0  
//启动子线程 Ghc U ~  
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; %?, 7!|Ls  
for(int i=0;i<nStartPos.length;i++) ZjY,k  
{ ^$}O?y7O  
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), k`&FyN^)  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), }V*?~.R  
nStartPos,nEndPos,i); `Tf}h8*  
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); ` &bF@$((  
fileSplitterFetch.start(); kvuRT`/  
} 6212*Z_Af  
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 'n>44_7L  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); %hN(79:g  
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", ,i|K} Y&  
nEndPos = " + nFileLength); ^/$dSXKF  
// fileSplitterFetch[nPos.length-1].start(); Y652&{>q  
ITg:OOQ  
,A $IFE  
//等待子线程结束 (F 9P1Iq  
//int count = 0; v#d(Kj  
//是否结束while循环 ~JNE]mg  
boolean breakWhile = false; MgJ5FRQ  
Ook\CK*nKe  
CM$&XJzva  
while(!bStop) rk4KAX_[  
{ ;Z`a[\i':  
write_nPos(); jMCd`Q]K  
Utility.sleep(500); _'1 7C /  
breakWhile = true; lZ)6d-vK  
xf/K+  
. AOc$Nt  
for(int i=0;i<nStartPos.length;i++) s,f2[6\Y  
{ ms;zC/  
if(!fileSplitterFetch.bDownOver) ]kx<aQ^  
{ ']fyD3N  
breakWhile = false; S.Kcb=;"L  
break; j,;f#+O`g  
} SXYwhID=  
} )/JVp>  
if(breakWhile) 8t=O=l\  
break;  maHz3:  
wr:W}Z@pL  
H ?9Bo!  
//count++; ("ix!\1K@  
//if(count>4) yUD@oOVC0  
// siteStop(); YgjW%q   
} |bSAn*6b  
{D^ )% {  
ULu@"  
System.err.println("文件下载结束!"); k{lo'  
} w'A*EWO  
catch(Exception e){e.printStackTrace ();} V6](_w!  
} :RukW.MR  
lK7:qo  
pfIK9>i  
//获得文件长度 xzOvc<u  
public long getFileSize() A'7Y{oPHX  
{ $H.U ~  
int nFileLength = -1; WRkuPj2  
try{ W( sit;O  
URL url = new URL(siteInfoBean.getSSiteURL()); :h(3Ep  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); B Tj1C  
httpConnection.setRequestProperty("User-Agent","NetFox"); N0}[&rE 8  
;<[!;8  
/DH`7E  
int responseCode=httpConnection.getResponseCode(); OmZZTeGg1s  
if(responseCode>=400) "PElQBLP:  
{ 0sKo NzE  
processErrorCode(responseCode); [ ^\{>m7  
return -2; //-2 represent access is error dc4XX5Z  
} aM1WC 'c&)  
COm^ ti-p  
3!@& 7@p  
String sHeader; #y7MB6-  
rA8NE>  
-c1-vGW/  
for(int i=1;;i++) qGR1$\]  
{ ujE~#b}X  
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); sx;/xIU|  
//Utility.log(in.readLine()); |oSt%l Q1  
sHeader=httpConnection.getHeaderFieldKey(i); A{B$$7%  
if(sHeader!=null) `L <sZ;Cj  
{ .t>SbGC  
if(sHeader.equals("Content-Length")) S1)g\Lv  
{ MIl\Bn  
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); ]j,o!|rx7  
break; NX(IX6^y  
} SeS ZMv  
} |x1Ttr,  
else K"g{P  
break; 5xnEkg4q4  
} IcQpb F0  
} <3tf(?*,k]  
catch(IOException e){e.printStackTrace ();} :jkPV%!~  
catch(Exception e){e.printStackTrace ();} fj( WH L  
>k@{NP2b  
k5tyOk  
Utility.log(nFileLength); []N&,2O  
G@~e :v)  
y c<%f  
return nFileLength; 0QquxYYw,  
} h82y9($cZ  
&WAU[{4W  
s2QgR37s>  
//保存下载信息(文件指针位置) \8a014  
private void write_nPos() Wt!;Y,1 s  
{ imwn)]LR  
try{ o](ORS$~  
output = new DataOutputStream(new FileOutputStream(tmpFile)); !IC .0I`  
output.writeInt(nStartPos.length); ^i WGGnGS  
for(int i=0;i<nStartPos.length;i++) bzZdj6>kX  
{ X2| Z!  
// output.writeLong(nPos); Bs`='w%7  
output.writeLong(fileSplitterFetch.nStartPos); oz:J.<j24Z  
output.writeLong(fileSplitterFetch.nEndPos); d3?gh[$  
} iH]0 YT.E  
output.close(); +JD^5J,-NJ  
} HlkjyD8  
catch(IOException e){e.printStackTrace ();} &.z-itiV  
catch(Exception e){e.printStackTrace ();} 54TWFDmGi  
} F/p1?1M  
Yu&\a?]\2  
FU}- .Ki  
//读取保存的下载信息(文件指针位置) X,o ]tgg=  
private void read_nPos() Gb Mu;CA  
{ iK'A m.o+  
try{ ka R55  
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); #&S<{75A  
int nCount = input.readInt(); B}p.fE  
nStartPos = new long[nCount]; "].TKF#yg  
nEndPos = new long[nCount]; yfFe%8w_vw  
for(int i=0;i<nStartPos.length;i++) .1J`>T?=Q  
{ +U<Ae^V  
nStartPos = input.readLong(); S*3$1BTl  
nEndPos = input.readLong(); \B/( H)Cd*  
} (lYC2i_b#  
input.close(); WYCDEoqU2  
} G8^b9xoA+.  
catch(IOException e){e.printStackTrace ();} Pj8Vl)8~NV  
catch(Exception e){e.printStackTrace ();} }gX4dv B  
} 5/m*Lc+r  
Ai)Q(]  
Z$YG'p{S  
private void processErrorCode(int nErrorCode) <bv9X?U  
{ G Wj !n  
System.err.println("Error Code : " + nErrorCode); T~}g{q,tR  
} X/Fip 0i  
&w%%^ +n |  
Pm24;'  
//停止文件下载 J(XK%e[8  
public void siteStop() nu|odP  
{ b%X}{/n  
bStop = true; }_Sgor83n  
for(int i=0;i<nStartPos.length;i++) i~HS"n  
fileSplitterFetch.splitterStop(); mUb2U&6(  
[vdC$9z,  
q>#P|  
} D{[i_K  
} Pc~)4>X<  
//负责部分文件的抓取 ;]/cCi  
**FileSplitterFetch.java JvW!w)$pY  
*/ ,Qe`(vU*s  
package NetFox; )GC[xo4bg  
aO\@5i_r  
dUceZmAl  
import java.io.*; DshRH>7s8  
import java.net.*; :J5CmU $  
wLQM]$O  
(%M:=zm  
public class FileSplitterFetch extends Thread { 9 &Od7Cn  
/dVcNo3"  
D%'rq  
String sURL; //File URL #M[Cq= 2  
long nStartPos; //File Snippet Start Position *K=me/ 3  
long nEndPos; //File Snippet End Position R*O6Z"h  
int nThreadID; //Thread's ID T5 BoOVgO  
boolean bDownOver = false; //Downing is over VK4"  
boolean bStop = false; //Stop identical W?12'EG}xa  
FileAccessI fileAccessI = null; //File Access interface JlH5 <:#PN  
OPKmYzf@b  
{+QQ<)l^tJ  
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException jRjQDK_"ka  
{ Rmh,P>  
this.sURL = sURL; <,T#* fg  
this.nStartPos = nStart; @eDL j}  
this.nEndPos = nEnd; yucbEDO.  
nThreadID = id; >LR+dShG  
fileAccessI = new FileAccessI(sName,nStartPos);//定位 BQ~&gy{  
} v{U1B  
w{ x=e  
QV%eTA  
public void run() zhwajc  
{ j7Lw( AJ  
while(nStartPos < nEndPos && !bStop) lG X_5R  
{ v[?eL0Z  
FEg&EYI  
s8kkf5bu  
try{ z*:.maq  
URL url = new URL(sURL); =G<S!qW  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); aw0xi,Jz  
httpConnection.setRequestProperty("User-Agent","NetFox"); akA C^:F  
String sProperty = "bytes="+nStartPos+"-"; |<7nf75c}  
httpConnection.setRequestProperty("RANGE",sProperty); s|8_R;  
Utility.log(sProperty); x"PMi[4  
&nF7CCF  
C  F<  
InputStream input = httpConnection.getInputStream(); d4-cZw}+  
//logResponseHead(httpConnection); .aR$ou,7  
<H!; /p/S  
B3Esfk  
byte[] b = new byte[1024]; P1QGfp0-J  
int nRead; RD p(Ci  
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) hLLg  
{ JSiLG0  
nStartPos += fileAccessI.write(b,0,nRead); QGd"Z lQ  
//if(nThreadID == 1) '^M3g-C[Jg  
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); b*qC  
} K<tkNWasQ  
8DNGqaH;dt  
*,__\/U98  
Utility.log("Thread " + nThreadID + " is over!"); ~ +z'pK~c  
bDownOver = true; I#hzU8Cc  
//nPos = fileAccessI.write (b,0,nRead); ;tLu  
} ag$UNV  
catch(Exception e){e.printStackTrace ();} lV!@h}mG  
} +2]{% =  
} w-MnJ(r  
%!1:BQ,p,i  
+EgQj*F*  
//打印回应的头信息 !~k-S exh  
public void logResponseHead(HttpURLConnection con) niN$!k+Jr  
{ )Ikx0vDFQ  
for(int i=1;;i++) ^?tF'l`  
{ >?A3;O]  
String header=con.getHeaderFieldKey(i); Lv ,Ls  
if(header!=null) (@?PN+68|  
//responseHeaders.put(header,httpConnection.getHeaderField(header)); 47XQZ-}4  
Utility.log(header+" : "+con.getHeaderField(header)); #r)c@?T@j  
else "eal Yveu  
break; P/FO,S-V  
} #fYz367>  
} bKH8/*Yk  
F/w!4,'<?5  
.Su9fj y%  
public void splitterStop() 'rdg  
{ Nl1v*9_x  
bStop = true; Jk7[}Jc$  
} vg1p{^N !  
E8Wgm 8  
)f0t"lk  
} !Hr +|HKQ?  
v 1O* Q  
b9([)8  
/* S\jN:o#b  
**FileAccess.java scUWI"  
*//文件访问(定位,写) =X2EF  
package NetFox; " U&   
import java.io.*; U vOB`Vj  
x_ \e&"x  
l$Y7CIH  
public class FileAccessI implements Serializable{ %-:6#b z  
8P'>%G<m  
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 C@L:m1fz  
RandomAccessFile oSavedFile; ?H3xE=<X  
long nPos;  _D(F[p|  
iffRGnN^e  
"ND 7,rQ  
public FileAccessI() throws IOException p_ QL{gn  
{ c>r0 N[  
this("",0); .)mw~3]  
} 9oY%v7  
h7  >  
uU>Bun  
public FileAccessI(String sName,long nPos) throws IOException @$;"nVZ4v  
{ sEL[d2oO  
oSavedFile = new RandomAccessFile(sName,"rw"); W$P)fPU'  
this.nPos = nPos; e p;_'  
oSavedFile.seek(nPos); C;;dCsiV5  
} pFD L5  
-$4PY,  
F,`y_71<  
public synchronized int write(byte[] b,int nStart,int nLen) -q\1Tlc]3  
{ BaTE59W  
int n = -1; NQ%lwE~  
try{ qMz0R\4  
oSavedFile.write(b,nStart,nLen); Wel-a< e  
n = nLen; @QMMtfeLj  
} 0=&Hm).  
catch(IOException e) !K1[o'o#  
{ #G^?4Z a  
e.printStackTrace (); r/fLm8+  
} [HK[{M =v=  
#Gs] u  
5"6Y=AuQ6  
return n; [:sV;37s  
} $} 7/mS@c  
-mG3#88*  
<D pi M`  
} qV.*sdS>  
+X0?bVT  
i}+K;,Da:8  
/* h{kAsd8 G  
**SiteInfoBean.java Je+z\eT!5<  
*/ !5Kv9P79  
package NetFox; pl V]hu27K  
+dk}$w[ g  
QVI4<Rxg  
public class SiteInfoBean { $GYcZN&  
ep Eg 6   
W)?B{\  
private String sSiteURL; //Site's URL >ZuWsA0q  
private String sFilePath; //Saved File's Path NS;,(v{*N  
private String sFileName; //Saved File's Name X[ }5hZcX  
private int nSplitter; //Count of Splited Downloading File uG2Hzav  
J(VJMS;_  
c:4M|t=  
public SiteInfoBean() *K'(t  
{//nSplitter的缺省值为5 `$7j:<c=  
//default value of nSplitter is 5 O!kBp(?]  
this("","","",5); kl_JJX6jPP  
} DnP>ed"M!  
a&p|>,WS  
tD.md _E  
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) |28z4.  
{  =h\,-8  
sSiteURL= sURL; ;dNKe.`Dg  
sFilePath = sPath; cRK1JxU  
sFileName = sName; [GX5jD#  
this.nSplitter = nSpiltter; 4}Y2 B$  
:e`;["(,  
~%B^`s  
} =M)+O%`*6  
u!];RHOp|  
1p<m>s=D=e  
public String getSSiteURL() Tz]t.]!&E  
{ yNP M-  
return sSiteURL; Z~ VOO7|m  
} ^i2W=A'P  
b'4{l[3~nl  
dQQh$*IL?{  
public void setSSiteURL(String value) pM= @  
{ c%yhODq/  
sSiteURL = value; K 38e,O  
} )"2)r{7:  
MJd!J ]E6  
HP^<2?K  
public String getSFilePath() h.E8G^}@  
{ /\V-1 7-  
return sFilePath; !v;N@C3C  
} O{uc  h  
!jGe_xB}~  
,&rlt+wE  
public void setSFilePath(String value) ;"$Wfy  
{ 0qqk:h  
sFilePath = value; 5fMVjd  
} 4R0'$Ld4  
F$y3oX  
$DeHo"mg7m  
public String getSFileName() 8e:J{EG~  
{ [QEV6 S]  
return sFileName; F~2bCy[Z  
} ) gbns'Z<  
$n\{6Rwb  
1%68Pnqk  
public void setSFileName(String value) ABw:SQ6=Q  
{  eme7y  
sFileName = value; nj$TdwZbK  
} Kur3Gf X  
]KdSwIbi  
iqm]sC`  
public int getNSplitter() VPoA,;Y"-  
{ mD<- <]SYp  
return nSplitter; #$2 {l,>  
} n]^zIe^6  
ul$k xc=N  
e` 9d&"  
public void setNSplitter(int nCount) 5gYv CW&~  
{ hkB/ OJ  
nSplitter = nCount; $5N%!  
} ],#Xa.r  
} Y S/x;  
jD1/`g%  
;c p*]  
/* 'c7C*6;a  
**Utility.java f 1s3pr??  
*/ U{/d dCf7  
package NetFox; Z0HfrK#oU  
=?]H`T:  
BdBwfH%:  
public class Utility { @yp#k>  
L/\s~*:M  
])F*)U  
public Utility() *?bOH5$@Nw  
{ >G7dw1;  
E/[>#%@i  
oGt,^!V1  
} 1T&NU  
{Tx"G9  
//线程睡眠 U; -2)+  
public static void sleep(int nSecond) >NLG"[\  
{ rlxZ,]ul  
try{ w5fVug/;P  
Thread.sleep(nSecond); #uTNf78X  
} _L?MYkD  
catch(Exception e) (D2G.R\pr  
{ S$#"bK/p^  
e.printStackTrace (); t5O '7x  
} ?APzb4f^W  
}  FZL"[3  
Gak@Z!|  
//日志 X83,f CCl5  
public static void log(String sMsg) O2xbHn4  
{ 3dO~Na`S  
System.err.println(sMsg); uoJ@Jt'j  
} K0;caqE^  
6g*?(Y][  
<pA%|]  
public static void log(int sMsg) "&Q sv-9t  
{ 2{U5*\FhVX  
System.err.println(sMsg); co^bS;r  
} `qoRnG  
} F8xz^UQO  
^mH:8_=(.  
To/6=$wto  
/* x%h4'Sm  
**TestMethod.java W%ml/ 4  
*/ 1t+uMhy*y  
package NetFox; L6d^e53AP  
-@7?N6~qZx  
S\76`Ot  
public class TestMethod { u~rPqBT{d3  
8'WoG]E_  
\/XU v(  
public TestMethod() %f)%FN . S  
{ ///xx/weblogic60b2_win.exe 79&=MTM  
try{ C#qF&n  
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); h2jrO9  
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); F\u]X  
SiteFileFetch fileFetch = new SiteFileFetch(bean); Z.}Z2K  
fileFetch.start(); "+XF'ZO  
} kz0pX- @b  
catch(Exception e){e.printStackTrace ();} #~}4< 18  
-%fc)y&$  
gQQve{'  
} 8|JPQDS7  
8I8{xt4   
z`H|]${X  
public static void main(String[] args) - +<ai  
{ h\T}$jgfWm  
new TestMethod(); PGd?c#v#  
} J,G/L!Bp  
} .R^R32ln  
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