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http断点续传简单实现(java)

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/* ! QKec  
**SiteFileFetch.java )o;n2T#O  
*/ aW#^@||B  
package NetFox; ]sqp^tQ`e  
import java.io.*; LAGg(:3f3  
import java.net.*; b~?3HY:t~K  
w ; PV &M  
A QPzId*z  
public class SiteFileFetch extends Thread { 6-\C?w A  
N::.o+1  
'EB5#  
SiteInfoBean siteInfoBean = null; //文件信息Bean b{,vZhP-  
long[] nStartPos; //开始位置 j?(@x>HA  
long[] nEndPos; //结束位置 .p'\@@o5  
FileSplitterFetch[] fileSplitterFetch; //子线程对象 #B__-"cRv  
long nFileLength; //文件长度 7 .xejz  
boolean bFirst = true; //是否第一次取文件 ,%KMi-w]q,  
boolean bStop = false; //停止标志 YVO~0bX:  
File tmpFile; //文件下载的临时信息 XeXK~  
DataOutputStream output; //输出到文件的输出流 !/Wv\qm  
CYNpbv  
//负责整个文件的抓取,控制内部线程(FileSplitterFetch类) ?xt${?KP  
public SiteFileFetch(SiteInfoBean bean) throws IOException _mDvRFq  
{ R/&C}6G n  
siteInfoBean = bean; }S9uh-j6l  
//tmpFile = File.createTempFile ("zhong","1111",new File(bean.getSFilePath())); zU# OjvNk  
tmpFile = new File(bean.getSFilePath()+File.separator + bean.getSFileName()+".info"); _2eL3xXha.  
if(tmpFile.exists ()) *B+YG^Yu^  
{ X'5+)dj  
bFirst = false; u2 U4MV1C  
read_nPos(); ;{rl Y>  
} d-"[-+)-  
else #Y>d@  
{ w*AXD!}  
nStartPos = new long[bean.getNSplitter()]; e{,[\7nF  
nEndPos = new long[bean.getNSplitter()]; BBsZPJ5  
} LESF*rh=  
L\^H#:?t  
@"`{Sh`Y$  
hF-X8$[  
} v?h8-yed  
(<#Ns W!z  
I`}x9t  
public void run() ]n:)W.|`R  
{ B[0XzV]Z  
//获得文件长度 }Ik{tUS$  
//分割文件 cTeEND)  
//实例FileSplitterFetch ' cl&S:  
//启动FileSplitterFetch线程 ctL@&~*nY  
//等待子线程返回 {^#62Y  
try{ \ oIVE+L/P  
if(bFirst) mSzBNvc i  
{ ToN$x^M w  
nFileLength = getFileSize(); ^.J F?2T/  
if(nFileLength == -1) ZAPT5  
{ MD ,}-m  
System.err.println("File Length is not known!"); lc=C  
} #U NTD4   
else if(nFileLength == -2) ~Cj55S+  
{ p_jDnb#  
System.err.println("File is not access!"); @hiwq 7[j  
} !z;a>[T'  
else DH_Mll>  
{ 1TKOvy_  
for(int i=0;i<nStartPos.length;i++) u4=j!Zb8}  
{ 5eO`u8M  
nStartPos = (long)(i*(nFileLength/nStartPos.length)); <m80e),~  
} D!~-53f@  
for(int i=0;i<nEndPos.length-1;i++) $@t-Oor;  
{ S"UFT-N  
nEndPos = nStartPos[i+1]; .foM>UOY  
} jl=<Q.Mm7  
nEndPos[nEndPos.length-1] = nFileLength; j3rBEQ,R  
} 2@o_7w98  
} DA@YjebP'  
0sRby!  
RR><so%  
//启动子线程 #{GUu ',?&  
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; |*7uF<ink6  
for(int i=0;i<nStartPos.length;i++) u7&r'rZ1_!  
{ >'/G:\M>A  
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), su(y*187A  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), H>e?FDs0*R  
nStartPos,nEndPos,i); S?%V o* Y  
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); YZf<S:  
fileSplitterFetch.start(); REhXW_x  
} viAvD6e  
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), phUno2fH  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); r+0"1\f3  
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", ;"&^ckP  
nEndPos = " + nFileLength); 2s;/*<WM  
// fileSplitterFetch[nPos.length-1].start(); I~MBR2$9  
yE-&TW_q:>  
@dcT8 YC  
//等待子线程结束 9tXLC|yl?  
//int count = 0; *"0Yr`)S  
//是否结束while循环 ,qpn4`zE~  
boolean breakWhile = false; ,-t3gc1~X  
J /'woc  
q,2]]K7y  
while(!bStop) `|i #)  
{ ` &|Rs  
write_nPos(); z?h\7 R  
Utility.sleep(500); x$AF0xFO  
breakWhile = true; qJFBdJU(1  
"tUXYY  
1^R@X  
for(int i=0;i<nStartPos.length;i++) 6!/e_a  
{ 1&Rz'JQ+  
if(!fileSplitterFetch.bDownOver) +}>whyX1  
{ Q$W0>bUP  
breakWhile = false; 31wact^  
break; =+97VO(w]G  
} B @UaaWh  
} 'rRo2oTN  
if(breakWhile) rOB-2@-  
break; xzy7I6X  
,Vt7Kiu  
'  G-]>  
//count++; a |32Pn  
//if(count>4) Rs{L  
// siteStop(); Qwk  
} oKz|hks[6  
Uq~{=hMX  
|h*H;@$  
System.err.println("文件下载结束!"); (}"r 5  
} s7SW4ff1  
catch(Exception e){e.printStackTrace ();} 4kNf4l9Y  
} BkJV{>?_+  
HLAWx/c,j"  
3ZU`}  
//获得文件长度 \S}&QV  
public long getFileSize() &m`1lxT  
{ vML01SAi  
int nFileLength = -1; ,2[laJ  
try{ u1ggLH!U  
URL url = new URL(siteInfoBean.getSSiteURL());  e1S |&W8  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); vX)JJ|g  
httpConnection.setRequestProperty("User-Agent","NetFox"); 4/S 4bk*8  
7h<Q{X<A  
LSNa  
int responseCode=httpConnection.getResponseCode(); %U)/>Z  
if(responseCode>=400) $91c9z;f^  
{ 22`W*e@6h  
processErrorCode(responseCode); p< '#f,o  
return -2; //-2 represent access is error 8Cs)_bj#!  
} q0.+F4  
 {IYfq)c  
gf2l19aP  
String sHeader; @YMef `T:  
G7pj.rQ  
8}\VlH]  
for(int i=1;;i++) .Frc:Y{  
{ 782be-n  
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); `&4L'1eF{  
//Utility.log(in.readLine()); K!5QFO4  
sHeader=httpConnection.getHeaderFieldKey(i); 234 OJ?  
if(sHeader!=null) F5gL-\6  
{ ?7@B$OlU  
if(sHeader.equals("Content-Length")) j=r`[B m  
{ c#$B;?  
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); 0V"r$7(}  
break; :qc@S&v@]  
} XN5EZ#  
} 8*H-</ =  
else \ZigG{  
break; S WVeUL#5  
} =2\k Jv3  
} nY'0*:'u  
catch(IOException e){e.printStackTrace ();} 1<fS&)^W  
catch(Exception e){e.printStackTrace ();} y!6B Gz  
ANc)igo  
kTAb <  
Utility.log(nFileLength); ixw3Z D(>+  
 &xgMqv2/  
s-}|_g.Pt  
return nFileLength; JWr:/?  
} bA@!0,m  
tU >wRw=d  
G6w&C^J*8>  
//保存下载信息(文件指针位置) A9Q!V01_  
private void write_nPos() F.HD;C-;(  
{ V'#dY~E-P  
try{ _~&6Kb^*  
output = new DataOutputStream(new FileOutputStream(tmpFile)); *$Z}v&-0k  
output.writeInt(nStartPos.length); iN"kv   
for(int i=0;i<nStartPos.length;i++) JC(rSs*  
{ $/Gvz)M  
// output.writeLong(nPos); VJDF/)X3$  
output.writeLong(fileSplitterFetch.nStartPos); >E|@3g +2  
output.writeLong(fileSplitterFetch.nEndPos); GRB/N1=  
} `$ZX]6G  
output.close(); Y|_ #yb  
} MGfDxHg]  
catch(IOException e){e.printStackTrace ();} @HxEp;*NH"  
catch(Exception e){e.printStackTrace ();} 6b~Zv$5^Y-  
} n`2 d   
c$rkbbf~V  
0Jm6 r4s?  
//读取保存的下载信息(文件指针位置) KiT>W~  
private void read_nPos() ,a eQXI#@  
{ 8;ke,x  
try{ S(.AE@U  
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile));  iE=Yh  
int nCount = input.readInt(); =<e|<EwSZ  
nStartPos = new long[nCount]; (wEaa'XL  
nEndPos = new long[nCount]; L@HPU;<  
for(int i=0;i<nStartPos.length;i++) l_hM,]T0  
{ P,k~! F^L  
nStartPos = input.readLong(); swYlp  
nEndPos = input.readLong(); kQ 7$,K#  
} WjW+ EF8(  
input.close(); 0^az<!!O#  
} :tp2@*] 9Z  
catch(IOException e){e.printStackTrace ();} =@AWw:!:,  
catch(Exception e){e.printStackTrace ();} V&;1n  
} J 05@SG':  
a|SgGtBtT4  
Rq )&v*=  
private void processErrorCode(int nErrorCode) [9(tIb!x  
{ t.$3?"60~  
System.err.println("Error Code : " + nErrorCode);  H;s  
} CnSfGsE>  
hEi]-N\X  
'iA#lKG  
//停止文件下载 GwQW I ]  
public void siteStop() k__iJsk  
{ XAwo ~E  
bStop = true; oG M Ls  
for(int i=0;i<nStartPos.length;i++) A-^[4&rb  
fileSplitterFetch.splitterStop(); Q1jU{  
Ig}G"GR  
lT#&\JQ  
} k"\%x =#  
} 6!dbJ5x1  
//负责部分文件的抓取 k!3X4;F!_  
**FileSplitterFetch.java |t+M/C0y/  
*/ g6{.C7m  
package NetFox; . <`i!Ls  
ig<Eyr  
[zl@7X1{_  
import java.io.*; _8P"/( `Rw  
import java.net.*; ) DXN|<A  
0]4kR8R3[  
gD10C,{  
public class FileSplitterFetch extends Thread { {a^A-Xh[u  
0B fqEAl  
o(w!x!["  
String sURL; //File URL k4fc 5P  
long nStartPos; //File Snippet Start Position .) uUpY%K^  
long nEndPos; //File Snippet End Position B4yU}v  
int nThreadID; //Thread's ID *GleeJWz  
boolean bDownOver = false; //Downing is over 74Xk^  8  
boolean bStop = false; //Stop identical PtCO';9[  
FileAccessI fileAccessI = null; //File Access interface NAjY,)>'K  
G6(k wv4  
Rt:k4Q   
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException Yv k Qh{  
{ d~F`q7F'?]  
this.sURL = sURL; ^`~M f  
this.nStartPos = nStart; _;(`u!@/{  
this.nEndPos = nEnd; ]Q,;5>#W  
nThreadID = id; /_<`#?5T(  
fileAccessI = new FileAccessI(sName,nStartPos);//定位 3[I; 3=O  
} _G%]d$2f`  
EBlfwFd  
W&CQ87b  
public void run() <k?ofE1o  
{ b~fX=!M  
while(nStartPos < nEndPos && !bStop) A<P3X/i  
{ bwo-9B  
KiYO,nD;\  
1c_gh12  
try{ q9fCoz  
URL url = new URL(sURL); ' QGacV   
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); B?A c  
httpConnection.setRequestProperty("User-Agent","NetFox"); KwK[)Cvv  
String sProperty = "bytes="+nStartPos+"-"; x{{QS$6v  
httpConnection.setRequestProperty("RANGE",sProperty); !$Aijd s5  
Utility.log(sProperty); ]T|9>o!  
Xou1X$$z  
[p[nK=&r  
InputStream input = httpConnection.getInputStream(); j(^ot001%v  
//logResponseHead(httpConnection); (Cjnf a 2  
^7M hnA  
n@n608  
byte[] b = new byte[1024]; d]1%/$v^  
int nRead; J$6h% Eyo  
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) zvjVM"=G  
{ a h<1&UG,  
nStartPos += fileAccessI.write(b,0,nRead); I@Zd<Rn  
//if(nThreadID == 1) h/~:}Bof  
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); _svEPHU  
} Y.` {]rC  
5v"r>q[ X  
W}m-5L  
Utility.log("Thread " + nThreadID + " is over!"); s2f9 5<B  
bDownOver = true; q-s! hiK  
//nPos = fileAccessI.write (b,0,nRead); ?#8',:  
} m|q?gX9R  
catch(Exception e){e.printStackTrace ();} ^0"^Xk*  
} AA][}lU:5  
} ~\= VSwJ  
*hVbjI$  
\b {Aj,6,  
//打印回应的头信息 Jf\lnJTyU8  
public void logResponseHead(HttpURLConnection con) x._IP,vRx^  
{ ?^Sk17G  
for(int i=1;;i++) XL[/)lX{  
{ gcYx-gA}  
String header=con.getHeaderFieldKey(i); _&S?uz m  
if(header!=null) 9pPb]v,6  
//responseHeaders.put(header,httpConnection.getHeaderField(header)); B$~oZ'4v  
Utility.log(header+" : "+con.getHeaderField(header)); 8N<0|u  
else #Mo`l/Cwp  
break; %bI(   
} [NcS[*qp  
} 6BIP;, M=  
^l1tQnj)7  
n^|;J*rD  
public void splitterStop() ~;St,Fw<<  
{ `@GqD  
bStop = true; 5 e:Urv77  
} mhnjY K9  
(H*-b4]/  
&tY3nr  
} H+ra w/"  
@rs(`4QEh  
FFXDt"i2  
/* TJ(PTB;  
**FileAccess.java NfLvK o8  
*//文件访问(定位,写) U$a Eby.  
package NetFox; iO=xx|d  
import java.io.*; 8+vZ9!7  
tq=1C=h  
1@IRx{v$  
public class FileAccessI implements Serializable{ 0z?b5D;  
K%LDOVE8e  
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 'G6TSl  
RandomAccessFile oSavedFile; eydVWVN  
long nPos; $mm =$.  
*Yv"lB8  
4mOw[}@A  
public FileAccessI() throws IOException !f_GR Pj'  
{ &_FNDJ>MCk  
this("",0); Rde_I`Ru  
} m%V+px  
3ojK2F(1D  
Wu)ATs}  
public FileAccessI(String sName,long nPos) throws IOException o;Ijv\Em  
{ Hxr2Q]c?u  
oSavedFile = new RandomAccessFile(sName,"rw"); b3b 4'l   
this.nPos = nPos; %sC,;^wla'  
oSavedFile.seek(nPos); oTtmn, T  
} tW5 \Ktjno  
H%7V)"  
>`*iM  
public synchronized int write(byte[] b,int nStart,int nLen) Ff>Y<7CQ v  
{ Y~1}B_  
int n = -1; VL5kjF3/  
try{ l^xkXj  
oSavedFile.write(b,nStart,nLen); ~l!(I-'?g  
n = nLen; *pP"u::S  
} A(_AOoA'  
catch(IOException e) e<5+&Cj  
{ IcL3.(!]l  
e.printStackTrace (); !boKrSw  
} 0w\X  
j>&n5?  
`'Ta=kd3  
return n; )xQxc.  
} ^a; V-US  
xmKa8']x  
==x3|^0y  
} qNHS 1  
UEo,:zeN[  
jbIWdHZ/US  
/* .u7d  
**SiteInfoBean.java rQ}4\PTi  
*/ B0p>'O2  
package NetFox; uW>AH@Pij  
/p\Ymq  
'5ky<  
public class SiteInfoBean { (m;P,*  
;YZw{|gsh  
("/*k  
private String sSiteURL; //Site's URL IX7d[nm39  
private String sFilePath; //Saved File's Path 0nx <f>n  
private String sFileName; //Saved File's Name I-/PzL<W P  
private int nSplitter; //Count of Splited Downloading File gY0*u+LF  
6FEtq,;0w  
 pMt]wyKr  
public SiteInfoBean() wT*N{).  
{//nSplitter的缺省值为5 Jq6p5jr"  
//default value of nSplitter is 5 [-6j4D  
this("","","",5); LV8,nTYvE  
} @Jm$<E  
}QJE9;<e  
,6t0w|@-k  
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) yr sP'th  
{ 0@AK  
sSiteURL= sURL; ; UrwK  
sFilePath = sPath; ?rBj{]=  
sFileName = sName; CKh-+8j  
this.nSplitter = nSpiltter; (|U+(~PJ  
`dL9sfj>  
"#4PU5.  
} ev8 E.ehD  
bO2$0!=I  
6Ir ?@O1'!  
public String getSSiteURL() 6bb=;  
{ TqQ>\h"&_  
return sSiteURL; |AFF*]e S  
} 1GEE^Eu  
WX0@H[$i#  
:eIB K  
public void setSSiteURL(String value) 7FMHz.ZRE  
{ ; $y.+5 q  
sSiteURL = value; sXhtn' <v  
} +,|-4U@dl  
)3..7ht3^5  
8<]> q  
public String getSFilePath() 6eS#L21*  
{ (9cIU2e  
return sFilePath; (b{ {B$O  
} RIJBHOa  
e9%6+ 9Y  
{Or|] 0  
public void setSFilePath(String value) w:umr#  
{ *E$D,  
sFilePath = value; sL\|y38'  
} <c\aZ9+V  
$iP#8La:Y  
ax 3:rl  
public String getSFileName() x65e,'  
{ @{ nT4{  
return sFileName; (O<lVz@8  
} RuXK` y Sv  
=vK(-h  
u5,IH2BU  
public void setSFileName(String value) ntF(K/~Y  
{ ' l!QGKz  
sFileName = value; Zv-6H*zM6  
} K GI]W|T  
ZO;]Zt]  
6Edqg   
public int getNSplitter() 'PO1{&M  
{ j2\G1@05  
return nSplitter; ~]yqJYiid^  
} 9<YB &:<  
A5/h*`Q\\  
ILVbbC`D  
public void setNSplitter(int nCount) X<?;-HrS;  
{ V2y[IeSQ  
nSplitter = nCount; D=OU61AA  
} s e1ipn_A  
} tou^p-)GQ|  
zCQv:.0L  
r;'!qwr  
/* <B fwR$  
**Utility.java + X ?jf.4  
*/ xz%ig^L  
package NetFox; bc"{ZL!C  
Vnl~AQfk|  
K:Ap|F  
public class Utility { @V-ZV  
6%'{Cq1DE  
3a5H<3w_  
public Utility() <AIsNqr  
{ K l4",  
)N=wJN1  
s R~&S))  
}  [:k'VXL  
;'Y?wH[  
//线程睡眠 \Dc\H )  
public static void sleep(int nSecond) p<+]+,|\~:  
{ X-duG*~  
try{ Z  b1v  
Thread.sleep(nSecond); OYzJE@r^  
} lAGxE-B^a"  
catch(Exception e) .dfTv/n  
{ =#u2Rx%V  
e.printStackTrace (); b'&pJ1]]}  
} }Q%>Fv  
} m<yA] ';s  
mSzwx/3"  
//日志 _5)#{ o<  
public static void log(String sMsg) Brl6r8LGi  
{ GGBe/X  
System.err.println(sMsg); Y[H_?f=;%  
} ^d"J2n,7L  
Y}Dp{  
oY] VP+b!  
public static void log(int sMsg) Ao\Vh\rQkq  
{ ^DH*@M  
System.err.println(sMsg); EK'&S=]  
} cU>&E* wD  
} H )}WWXK  
Z^|C~lp;n  
e!8_3BE  
/* y"hM6JI  
**TestMethod.java rEf\|x=st:  
*/ <\8   
package NetFox; C0W~Tk\C2  
Gh pd k;  
t[maUy _A  
public class TestMethod { D 6]$P%t9  
@r43F$bcqo  
5 QeGx3'  
public TestMethod() I Q L~I13  
{ ///xx/weblogic60b2_win.exe %(Ys-GeGr  
try{ n96gDH*  
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); NQJqS?^W&M  
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); #R8l"]fxr?  
SiteFileFetch fileFetch = new SiteFileFetch(bean); =tNiIU  
fileFetch.start(); 8?YW i  
} ##@#:B  
catch(Exception e){e.printStackTrace ();} $iPN5@F  
>FHsZKJ  
jq]"6/xxb  
} {|h"/   
>>cd3)b  
Ltw7b  
public static void main(String[] args) 48Lmy<}*  
{ `.W;ptZ6  
new TestMethod(); D.o|($S0  
} `Cf en8  
} j*u9+.   
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