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http断点续传简单实现(java)

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/* ig")bt3s5  
**SiteFileFetch.java 9RE{,mos2v  
*/ Z, lUO.  
package NetFox; ":Kn@S'{(  
import java.io.*; }2:bYpYQ  
import java.net.*; ?\<2*sW [k  
GH7{_@pv8  
P9B@2#  
public class SiteFileFetch extends Thread { Bag2sk  
e%R+IH5i  
SV<*qz  
SiteInfoBean siteInfoBean = null; //文件信息Bean hIXGfvUy  
long[] nStartPos; //开始位置 QTz{ZNi!  
long[] nEndPos; //结束位置 #h6(DuViKw  
FileSplitterFetch[] fileSplitterFetch; //子线程对象 &VY;Al  
long nFileLength; //文件长度 = <O{t#]  
boolean bFirst = true; //是否第一次取文件 +y6|Nq  
boolean bStop = false; //停止标志 zv@'x nY]  
File tmpFile; //文件下载的临时信息 ojs&W]r0Z  
DataOutputStream output; //输出到文件的输出流 q&<#)#+  
/q uf'CV}  
//负责整个文件的抓取,控制内部线程(FileSplitterFetch类) W ;P1T"*A  
public SiteFileFetch(SiteInfoBean bean) throws IOException ' uo`-Y  
{ d;m Q=k 1  
siteInfoBean = bean; p? iJ'K  
//tmpFile = File.createTempFile ("zhong","1111",new File(bean.getSFilePath())); c~5#)AXMT  
tmpFile = new File(bean.getSFilePath()+File.separator + bean.getSFileName()+".info"); N5}vy$t_P  
if(tmpFile.exists ()) 1.p?P] .  
{ 9(ZzwkD'>  
bFirst = false; Uf4QQ `c#  
read_nPos(); ?OZbns~  
} S4qh8c  
else }E*d)n|  
{ wju~5  
nStartPos = new long[bean.getNSplitter()]; r?{Vqephz  
nEndPos = new long[bean.getNSplitter()]; Gxi;h=J2)>  
} JEdtj1v{O  
ii2oWU  
\CUxGyu  
g"(N_sv?  
} pcur6:8W!  
a}i{b2B  
'8*gJ7]  
public void run()  7z<!2  
{ /nv1 .c)k  
//获得文件长度 u\t[rC=yd  
//分割文件 [O"i!AQ  
//实例FileSplitterFetch 2O<S ig=  
//启动FileSplitterFetch线程 )P|%=laE8  
//等待子线程返回 {)4Vv`n  
try{ F#X\}MvEU  
if(bFirst) L9Fx Lw41  
{ .Z%7+[  
nFileLength = getFileSize(); px//q4 U  
if(nFileLength == -1) Pk8L- [&v  
{ 2*K0~ b`  
System.err.println("File Length is not known!"); 0qG[hxt%  
} ^>%=/RX  
else if(nFileLength == -2) }K<;ygcWE@  
{ ?=r!b{9  
System.err.println("File is not access!"); {D."A$AAa  
} nz+o8L,  
else 1yX&iO^d  
{ ;4 ?%k )  
for(int i=0;i<nStartPos.length;i++) D.*JG7;=Z  
{ P%ZWm=lg  
nStartPos = (long)(i*(nFileLength/nStartPos.length)); GdG%=+  
} |i|YlWQS  
for(int i=0;i<nEndPos.length-1;i++) EF"ar  
{ T?AGQcG  
nEndPos = nStartPos[i+1]; Y1`.  
} s$H5W`3  
nEndPos[nEndPos.length-1] = nFileLength; ;lYO)Z`3\  
} Mh~T.;f.qq  
} V9Au\  
MYN1zYT6j  
8^dGI9N  
//启动子线程 YQQ!1 hw  
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; YgM6z K~  
for(int i=0;i<nStartPos.length;i++) {H])Fob  
{ PDD` eK}Fj  
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), g:[&]o} :9  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), 6O tv[8^}  
nStartPos,nEndPos,i); }ZVNDvGH  
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); /jj@ =H  
fileSplitterFetch.start(); U-WrZ|-  
} \R79^  
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), p-*BB_J"  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); Xo%Anqk  
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", fi bR:8  
nEndPos = " + nFileLength); 3g-}k  
// fileSplitterFetch[nPos.length-1].start(); tCc}}2bC&  
h$ZF[Xbfe  
1"v;w!uh  
//等待子线程结束 1d\K{ 7i#  
//int count = 0; *,'"\n  
//是否结束while循环 t8?+yG;  
boolean breakWhile = false; N"E\o,_  
ioa 1n=j  
i w m7M  
while(!bStop) P]6pPS  
{ c$e~O-OVD?  
write_nPos(); fcw \`.  
Utility.sleep(500); .zegG=q  
breakWhile = true; Llk`  
9 z3Iwl  
{<kl)}  
for(int i=0;i<nStartPos.length;i++) :"QRB#EC%  
{ w~Y#[GW  
if(!fileSplitterFetch.bDownOver) 2ZE4^j|  
{ 6PPvf D^  
breakWhile = false; (>;~((2  
break; }:jXl!:V  
} UI!EIZ*~  
} uk\GAm@O  
if(breakWhile) pn =S%Qf]  
break; gl!3pTC  
l;|1C[V  
8=2)I.   
//count++; P AKh v.7  
//if(count>4) mS%D" e  
// siteStop(); SnXYq 7`t  
} ~V./*CQ\c  
D2?7=5DgS  
lT(MywNsg  
System.err.println("文件下载结束!"); Y: byb68  
} ?ii a  
catch(Exception e){e.printStackTrace ();} Zmp ^!|=X!  
} h[lh01z  
N86Hn]#  
lq%s/l  
//获得文件长度 #[i({1`^L  
public long getFileSize() 9JUlu  
{ /\=g;o'  
int nFileLength = -1; _Y~+ #Vc  
try{ .79'c%3}  
URL url = new URL(siteInfoBean.getSSiteURL()); }2h~o~  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); YE^|G,]  
httpConnection.setRequestProperty("User-Agent","NetFox"); Ybok[5  
6~2!ZU  
$Z;0/\r%  
int responseCode=httpConnection.getResponseCode(); EL+}ab2S  
if(responseCode>=400) ;ga~ae=Fg  
{ Z+vLEEX*uQ  
processErrorCode(responseCode); 4)"jg[  
return -2; //-2 represent access is error N*$Q(K  
} e{?~ m6  
5q8bM.k\7N  
].Et&v  
String sHeader; \?GMtM,  
3-Ti'xM  
.IYE"0)wJ  
for(int i=1;;i++) y t<K!=7&  
{ ^ 5UIbA(  
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); Qb SX'mx<  
//Utility.log(in.readLine()); c5t?S@b  
sHeader=httpConnection.getHeaderFieldKey(i); "0]i4d1l  
if(sHeader!=null) V= .'Db2D  
{ W{0<ro`  
if(sHeader.equals("Content-Length")) D vK}UAj=  
{ p oNQ<ijK  
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); l$zM|Z1wR`  
break; PVU(R J  
} {j^}"8GB  
} D&]SPhX  
else ci*Z9&eS+  
break; X"[c[YT!%[  
} >Ks|yNJ  
} #|gt(p]C  
catch(IOException e){e.printStackTrace ();} P [gqv3V  
catch(Exception e){e.printStackTrace ();} D+k5e=  
scA&:y  
pET5BMxGG  
Utility.log(nFileLength); 8-po|  
PR.?"$!D{  
^(a%B  
return nFileLength; 0P!6 .-XU  
} QRa>W/N  
!qy/'v4  
)WBTqML[  
//保存下载信息(文件指针位置)  C9*'.~  
private void write_nPos() _STN^   
{ A!hkofQ  
try{  DMf:u`<  
output = new DataOutputStream(new FileOutputStream(tmpFile)); :GO}G`jY  
output.writeInt(nStartPos.length); \]o#tYN\a0  
for(int i=0;i<nStartPos.length;i++) yyBy|7QgO  
{ Qs*g)Yr  
// output.writeLong(nPos); Y.=v!*p?}  
output.writeLong(fileSplitterFetch.nStartPos); M3x%D)*  
output.writeLong(fileSplitterFetch.nEndPos); o,u-%  
} Q;`#ujxL  
output.close(); p5Y"W(5_  
} r6j 3A  
catch(IOException e){e.printStackTrace ();} `F(KM '  
catch(Exception e){e.printStackTrace ();} ^ b}_[B  
} bl:.D~@  
jYuH zf  
 &grT}  
//读取保存的下载信息(文件指针位置) -4"E]f  
private void read_nPos() Oi=kL{DG:s  
{ up`!r;5-  
try{ {6A3?q  
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); LUJKR6oT{>  
int nCount = input.readInt();  :3u>%  
nStartPos = new long[nCount]; @@_f''f$  
nEndPos = new long[nCount]; @Vc*JEW  
for(int i=0;i<nStartPos.length;i++) `|Tr"xavf  
{ k%Jw S_F  
nStartPos = input.readLong(); JZN'U<R  
nEndPos = input.readLong(); 41,Mt  
} W}nD#9tL  
input.close(); $I+QyKO9k  
} HPm12&8,  
catch(IOException e){e.printStackTrace ();} C:zK{+  
catch(Exception e){e.printStackTrace ();} @ Al\:  
} nIKh<ws4z  
^P\(IDJCo  
?r#e  
private void processErrorCode(int nErrorCode) EubF`w$KWX  
{ .J'}qkz~  
System.err.println("Error Code : " + nErrorCode); T/uj5pMG  
}  Wu9@Ecb  
Al6)$8]e   
oJ>]=^?k  
//停止文件下载 %Q rf ]  
public void siteStop() <<Ut@243\  
{ (*BQd1Z  
bStop = true; EO3?Dev  
for(int i=0;i<nStartPos.length;i++) 7k{C'\m  
fileSplitterFetch.splitterStop(); iIA&\'|;i  
'$;S?6$eW  
jBarYg  
} Hj$JXo[U  
} 6:#zlKYJ  
//负责部分文件的抓取 i4&"-ujrm  
**FileSplitterFetch.java Tf<1Z{9  
*/ F3i+t+Jt  
package NetFox; 4tof[n3us  
z45ImItH  
$9j\sZj&  
import java.io.*; ; Sq_DP1W  
import java.net.*; tJ i#bg%  
b_:]Y<{> f  
9v8{JaI3  
public class FileSplitterFetch extends Thread { TE3A(N'  
iE!\)7y  
-: dUD1  
String sURL; //File URL g,r'].Jg  
long nStartPos; //File Snippet Start Position #jv~FR`4v^  
long nEndPos; //File Snippet End Position 8dNwi&4  
int nThreadID; //Thread's ID $&I##od  
boolean bDownOver = false; //Downing is over S{zi8Oc6  
boolean bStop = false; //Stop identical :4;ZO~eq!  
FileAccessI fileAccessI = null; //File Access interface YJ3aJ^m#E  
Ao69Qn  
{+F/lN@  
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException bM; ==W  
{ ]ECzb/  
this.sURL = sURL; @~qlSU&  
this.nStartPos = nStart; u`O xY  
this.nEndPos = nEnd; P=OHiG\z  
nThreadID = id; #;# V1  
fileAccessI = new FileAccessI(sName,nStartPos);//定位 4 >at# Zc  
} yF0\$%H>$  
9,sj,A1  
"k o?AUt  
public void run() Lo5itW  
{ K?8{ y  
while(nStartPos < nEndPos && !bStop) rzsb(  
{ 8vOKm)[%  
c,:xm=&  
6-c3v  
try{ :GBWQXb G  
URL url = new URL(sURL); & gnE"  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); , `ST Va-  
httpConnection.setRequestProperty("User-Agent","NetFox"); F#*vJb)  
String sProperty = "bytes="+nStartPos+"-"; *$1M= $  
httpConnection.setRequestProperty("RANGE",sProperty); u^8:/~8K  
Utility.log(sProperty); @`^+XPK\  
0&} "!)  
wt0^R<28  
InputStream input = httpConnection.getInputStream(); B"ZW.jMaI  
//logResponseHead(httpConnection); .DiH)  
8*-8"It<"  
tpwMy:<Ex  
byte[] b = new byte[1024]; 7O^ySy"l  
int nRead; mEyJ o|  
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) ]3u ErnI  
{ Ne!F  p  
nStartPos += fileAccessI.write(b,0,nRead); mtSOygd  
//if(nThreadID == 1) ,u8)g; 8s  
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); ms@*JCL!t  
} ^V#9{)B  
FAkjFgUJp  
"7mY s)=  
Utility.log("Thread " + nThreadID + " is over!"); RB`Emp&T  
bDownOver = true; #  -e  
//nPos = fileAccessI.write (b,0,nRead); WvQK$}Ax4N  
} rJ|Q%utYz  
catch(Exception e){e.printStackTrace ();} DN3#W w2[r  
} (Z;;v|F.i=  
} <5X?6*Qvr  
r~&"D#)sy  
SAMP,un7  
//打印回应的头信息 ;jS2bc:8a  
public void logResponseHead(HttpURLConnection con) FR&4i" +  
{ YNyaz\L  
for(int i=1;;i++) MB06=N  
{ ?f<JwF<  
String header=con.getHeaderFieldKey(i); %xF j;U?  
if(header!=null) azF|L"-RP  
//responseHeaders.put(header,httpConnection.getHeaderField(header)); (L}  
Utility.log(header+" : "+con.getHeaderField(header)); rH Et]Xa  
else FKRO0%M4}Z  
break; #}*w &y  
} 78zjC6}`  
} (hWr!(>C4]  
\n$s5i-  
G- wQ weJ9  
public void splitterStop() +aR.t@D+"Y  
{ pESlBQ7{I  
bStop = true; =oQw?,eY  
} +y'V  
^PA >t$  
x(pq!+~K  
} |U)m'W-(q  
G347&F)  
d*Q:[RUf,  
/* itClCEOA  
**FileAccess.java ~'>RK  
*//文件访问(定位,写) E^B*:w3  
package NetFox; H<T9$7Yr%r  
import java.io.*; {C3AxK0  
3 r4QB  
|`d,r.+P7  
public class FileAccessI implements Serializable{ y"q7Gx*^j  
\9k$pC+l  
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 l`=).k   
RandomAccessFile oSavedFile; 65X31vU  
long nPos; x}o]R  
l}odW  
 t9T3e  
public FileAccessI() throws IOException <{ !^  
{ wgfy; #  
this("",0); 2r;^OWwr?  
} 1&N|k;#QS  
:&: IZkO  
;]YQ WK  
public FileAccessI(String sName,long nPos) throws IOException y Nb&;E7 H  
{ /xf4*zr  
oSavedFile = new RandomAccessFile(sName,"rw"); :a$ZYyD  
this.nPos = nPos; / !J1}S  
oSavedFile.seek(nPos); v l59|W6  
} BMPLL2I  
cfI5KLG~#  
U U!M/QJ  
public synchronized int write(byte[] b,int nStart,int nLen) vQf'lEFk  
{ FD>j\  
int n = -1; Zkl:^!*  
try{ kw)@[1U  
oSavedFile.write(b,nStart,nLen); `s74g0h  
n = nLen; kB_uU !G  
} ] =ar&1}J  
catch(IOException e) .C=&` ;Vs  
{ 3&i8C,u]/O  
e.printStackTrace (); kcT?<r  
} *4}l V8  
S~^0 _?  
&X0/7)*"v  
return n; nsR^TD;  
} uV1H iv-  
bDd$79@m  
bSHlR#!6  
} N_S>%Z+  
:()(P9?  
{MX_t/o=f  
/* 86d *  
**SiteInfoBean.java | rJ_  
*/ %4QCUc*lr  
package NetFox; dLOUL9hf  
N{Og; roGD  
xR+=F1y  
public class SiteInfoBean { f:iK5g  
Ht^MY  
=w &%29BYq  
private String sSiteURL; //Site's URL [{3WHS.  
private String sFilePath; //Saved File's Path ,Yhy7w  
private String sFileName; //Saved File's Name $$C5Q;7w!  
private int nSplitter; //Count of Splited Downloading File  v|+}>g  
VuTH"br6  
K@xp!  
public SiteInfoBean() m(JFlO  
{//nSplitter的缺省值为5  (2vR8  
//default value of nSplitter is 5 /_~b~3{u  
this("","","",5); 'Rk~bAX  
}  |u 8hxa  
X;_0"g  
c)Ft#vzg&e  
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) Mi'Q5m  
{ uYjJDLYoHl  
sSiteURL= sURL; kfb+OE:7  
sFilePath = sPath; 0^44${bA  
sFileName = sName; 3}O.B r|  
this.nSplitter = nSpiltter; g3{)AX[Uy  
e #l/jFJU  
Wo5G23:xz  
} bu"Jb4_a>  
N]cGJU>$  
=DTn9}u  
public String getSSiteURL() gOw|s1`2,  
{ ~D@pk>I  
return sSiteURL; )CS 7>Vx  
} AEkgm^t.{  
&*g5kh{  
U@[P.y~J  
public void setSSiteURL(String value) Y1AbG1n|  
{ EK. L>3  
sSiteURL = value; }]sI?&xB  
} ><iEVrpN  
#I9|>XE1  
DoWY*2E  
public String getSFilePath() dtjaQsJM^  
{ xD#PM |I  
return sFilePath; lD2>`s 5  
} @Zd+XWFw  
}4xxge?r  
KmV#% d  
public void setSFilePath(String value) ]OY6.m  
{ yAEOn/.~  
sFilePath = value; g=; rM8W  
} j-$aa;  
l1`Zp9I  
6,  ag\  
public String getSFileName() <Xw 6m$fr:  
{ ;}K1c+m!5V  
return sFileName; ^8)&~q*  
} U0u@[9!  
D+rDgrv  
GSV,  
public void setSFileName(String value) #Q6wv/"Ub  
{ S6}_Z  
sFileName = value; d T/*O8  
} &nn!{S^  
/6F 1=O(c>  
@FkNT~OZ  
public int getNSplitter() &dvJg  
{ 7=om /  
return nSplitter; *Q=-7a m  
} 6N.mSnp  
0]8+rWp|Nz  
FVG|5'V^  
public void setNSplitter(int nCount) 3leg,q d  
{ H*|Bukgt/M  
nSplitter = nCount; &.kg8|s{  
} t,N- |  
} .5L/<  
s5|LD'o!  
w;H  
/* wO} 3i6  
**Utility.java P?n!fA>!  
*/ O~d!* A  
package NetFox; ^'QcP5Fv  
oD{V_/pdx  
A#1aO  
public class Utility { f]T1:N*t  
 g/+M&k$  
$$ _ uQf  
public Utility() hl}#bZ8]  
{ KtEM H  
/G[y 24 Q  
\Qk:\aLR  
} y(.WK8  
!nVX .m9  
//线程睡眠 IvIBf2D;Q  
public static void sleep(int nSecond) NL&g/4A[a  
{ &%u,b~cL?  
try{ |BH, H  
Thread.sleep(nSecond); k`)LO`))  
} M#S8x@U  
catch(Exception e) 3Un/-4uL  
{ F]yclXf('  
e.printStackTrace (); r\],5x'xSu  
} ~R)w 9uq  
} @{I55EQ]  
"G6d'xkP  
//日志 idO3/>R [  
public static void log(String sMsg) G&C)`};  
{ ?2EzNNcS  
System.err.println(sMsg); GU&XK7L  
} U\VwJ2 {i  
ie.cTTOI  
vp mSzh  
public static void log(int sMsg) 7C2/^x P  
{ Qg 6m  
System.err.println(sMsg); A9l^S|r  
} }f&7<E  
} )CR8-z1`  
t 1C{  
1b|<   
/* #s yP=  
**TestMethod.java HqYaQ~Dth  
*/ y_$^Po  
package NetFox; G#@<bg3  
;k/0N~  
P\zi:]h[Gh  
public class TestMethod { n+uq|sYVa  
)1x333.[c  
(OG@]|-  
public TestMethod() mz\ m^g3  
{ ///xx/weblogic60b2_win.exe >MQW{^  
try{ -IX;r1UD  
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); 82/iVm1  
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); K=(&iq!VO  
SiteFileFetch fileFetch = new SiteFileFetch(bean); gu:..'V  
fileFetch.start(); ;'o>6I7Ph  
} ?N|PgNu X  
catch(Exception e){e.printStackTrace ();} @XIwp2A{+  
'.kbXw0}  
*;gi52tM  
} {Z?!*Ow  
z0Zl'  
Y(A?ib~K  
public static void main(String[] args) |g;XC^!%=o  
{ sJM}p5V  
new TestMethod(); IBF>4q m"  
} i-ogeR?  
} pwZ &2&|  
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