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http断点续传简单实现(java)

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/* kCD] &  
**SiteFileFetch.java eb`3'&zV&)  
*/ :@jctH~  
package NetFox; %ZD]qaU0  
import java.io.*; W7 A!QS  
import java.net.*; Ox#vW6;)  
G7Ck P  
F-zIzzb&O  
public class SiteFileFetch extends Thread { h[qZM  
U - OD  
-V;Y4,:c  
SiteInfoBean siteInfoBean = null; //文件信息Bean l4i 51S"  
long[] nStartPos; //开始位置 >vo 6X]p~  
long[] nEndPos; //结束位置 -){6ynqv  
FileSplitterFetch[] fileSplitterFetch; //子线程对象 ,gZp/yJ;  
long nFileLength; //文件长度 o_Z9\'u  
boolean bFirst = true; //是否第一次取文件 ZqrS]i@$  
boolean bStop = false; //停止标志 ?" 4X&6xl  
File tmpFile; //文件下载的临时信息 8y6dT  
DataOutputStream output; //输出到文件的输出流 *#>(P  
pLe4dz WA  
//负责整个文件的抓取,控制内部线程(FileSplitterFetch类) @2. :fK  
public SiteFileFetch(SiteInfoBean bean) throws IOException eE'>kP}  
{ r e zp7  
siteInfoBean = bean; &&l ZUR,`  
//tmpFile = File.createTempFile ("zhong","1111",new File(bean.getSFilePath())); L&s~j/ pR  
tmpFile = new File(bean.getSFilePath()+File.separator + bean.getSFileName()+".info"); {1Cnrjw  
if(tmpFile.exists ()) c-JXWNz  
{ mZB:j]T  
bFirst = false; \Y"S4<"R  
read_nPos(); 0 cKsGDm  
} 2;T?ry7  
else ?bM%#x{e  
{ Uf+y$n-  
nStartPos = new long[bean.getNSplitter()]; : 8>zo  
nEndPos = new long[bean.getNSplitter()]; bC+Z R{M  
} Epp>L.?r  
.S|T{DMQ[  
j;uUM6  
> "rM\ Q  
} %[KnpJ{\  
nI?*[y}  
@d{}M)6\!  
public void run() *LhwIY  
{ 1 Q FsT  
//获得文件长度 1lIs jBo g  
//分割文件 IY6Ll6OK  
//实例FileSplitterFetch X%s5D&gr  
//启动FileSplitterFetch线程 Z*w({k7]  
//等待子线程返回 n:4 0T1: q  
try{ ,=CipL9]  
if(bFirst) \?v&JmEU  
{ qspGNu  
nFileLength = getFileSize(); X\!q8KEpR&  
if(nFileLength == -1) MF.!D;s  
{ IW i0? V  
System.err.println("File Length is not known!"); P=EZ6<c3&  
} 9\?&u_ U"  
else if(nFileLength == -2) $]#8D>E&  
{ N)cODy([  
System.err.println("File is not access!"); T_2'=7  
} 3(J>aQZuI  
else uY)4y0  
{ 7Fpa%N/WL  
for(int i=0;i<nStartPos.length;i++) EwG+' nlE  
{ )M Iw/  
nStartPos = (long)(i*(nFileLength/nStartPos.length)); HLz<C  
} ha|2u(4  
for(int i=0;i<nEndPos.length-1;i++) \mu';[gLd  
{ vM5I2C3_>!  
nEndPos = nStartPos[i+1]; @=w)a  
} {(-923|,  
nEndPos[nEndPos.length-1] = nFileLength; 0y<9JvN$9  
} 9Oj b~  
} Mz$qe  
b/\O;o}]  
Z(RsB_u5  
//启动子线程 )x [=}0C  
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; m`zd0IRTP  
for(int i=0;i<nStartPos.length;i++) w7~]c,$y.  
{ chD7 ^&5]  
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), bny@AP(CY+  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), _Q^jk0K8ga  
nStartPos,nEndPos,i); =aj|auu  
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); &/uakkS  
fileSplitterFetch.start(); U[;ECw@  
} exSwx-zxI  
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), TuCHD~rb  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); 1 c"s+k]9  
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", o/ \o -kC}  
nEndPos = " + nFileLength); 6flO;d/v  
// fileSplitterFetch[nPos.length-1].start(); Us "G X_  
Ap\]v2G  
3@eI? (N  
//等待子线程结束 Kg2@]J9m  
//int count = 0; Vt zSM%=  
//是否结束while循环 xF) .S@  
boolean breakWhile = false; *]q`:~u2  
</<z7V,{  
n@@tO#!\  
while(!bStop) tZ=|1lM  
{ /Tl ybSC1  
write_nPos(); )N{PWSPs  
Utility.sleep(500);  ]igCV  
breakWhile = true; Th,]nVsGs~  
E.$//P n|1  
eWYet2!Q  
for(int i=0;i<nStartPos.length;i++) `m AYK)N  
{ ]lJ#|zd8o  
if(!fileSplitterFetch.bDownOver) >oy%qLHe~t  
{ Jp)PKS ![  
breakWhile = false; Gg6cjc=dC  
break; \K9Y@jnr  
} coaJDg+  
} '%Oo1:wJ  
if(breakWhile) $?: -A  
break; b,HXD~=  
&C,]c#-+  
3S^Qo9S  
//count++; YA8/TFu<_  
//if(count>4) mNe908Yw  
// siteStop(); m|cRj{xZF  
} 3s:)CXO  
<C"}OW8  
Obc,    
System.err.println("文件下载结束!"); N]c:8dOj  
} /%?bO-  
catch(Exception e){e.printStackTrace ();} >)+U^V  
} uTbMp~cYB  
*qMjoP,  
~U?vB((j!  
//获得文件长度 &n6 |L8  
public long getFileSize() u_WW uo  
{ NFIFCy!  
int nFileLength = -1; }?{. 'Hv0  
try{ T^ xp2cZ  
URL url = new URL(siteInfoBean.getSSiteURL()); d9D*w/clMi  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); #2.C$  
httpConnection.setRequestProperty("User-Agent","NetFox"); 5hCfi  
^kB9 I8u  
0Z%<H\Z  
int responseCode=httpConnection.getResponseCode(); P#A|Pn<p  
if(responseCode>=400) 8r\xQr'8h  
{ Q"xDRQA  
processErrorCode(responseCode); jT QN(a9Y  
return -2; //-2 represent access is error Pt;\]?LVrD  
} ~ C_2D?  
Q%GLT,f1.  
^eYJ7&t  
String sHeader; f'Xz4;  
1^;&?E  
8{Svax(  
for(int i=1;;i++) I#p-P)Q%S  
{ v#sx9$K T  
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); ^T@-yys  
//Utility.log(in.readLine()); .fW`/BXE  
sHeader=httpConnection.getHeaderFieldKey(i); V|0UwS\n  
if(sHeader!=null) VKrKA71Z~  
{ Z3T26Uk  
if(sHeader.equals("Content-Length")) / dn]`Ge)  
{ R91u6r#  
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); 3^ &pb  
break; t;ga>^NA"  
} RzSN,bL R  
} p7O4CP>9[  
else U`'w{~"D%  
break; :(x 90;DW  
} !C0= h  
} b}q,cm  
catch(IOException e){e.printStackTrace ();} WUi7~Ei}  
catch(Exception e){e.printStackTrace ();} %}&9[#  
L' h'm{i  
xhMdn3~U  
Utility.log(nFileLength); 2I39fZa  
Y!s/uvRI  
V'?nS&,i  
return nFileLength; WqU$cQD"  
} 5O%}.}n  
*m]%eU(  
|b7>kM}"  
//保存下载信息(文件指针位置) {k~$\J?.  
private void write_nPos() ae1fCw3k  
{ ]R]X#jm  
try{ 9p$q@Bc  
output = new DataOutputStream(new FileOutputStream(tmpFile)); 8@Km@o]?  
output.writeInt(nStartPos.length); J5rR?[i{  
for(int i=0;i<nStartPos.length;i++) )'<zC  
{ bm7$DKp#  
// output.writeLong(nPos); r*3XM{bZ/@  
output.writeLong(fileSplitterFetch.nStartPos); QnOa?0HL/  
output.writeLong(fileSplitterFetch.nEndPos); p|bpE F=U  
} ~E`A,  
output.close(); IweQB}d  
} uTJ?@ ^nq  
catch(IOException e){e.printStackTrace ();} Cw^)}23R  
catch(Exception e){e.printStackTrace ();} EGMcU| yL  
} wy&*6>.  
T@ HozZ  
#QDV_ziE5  
//读取保存的下载信息(文件指针位置) Pr/&p0@aV  
private void read_nPos() CC87<>V  
{ nocH~bAf2  
try{ 1Q;` <=  
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); ) DLK<10  
int nCount = input.readInt();  3i$AR  
nStartPos = new long[nCount]; rC*nZ*  
nEndPos = new long[nCount]; |$0/:*  
for(int i=0;i<nStartPos.length;i++) SI(8.$1  
{ |m EJJg`"7  
nStartPos = input.readLong(); %yrP: fg/  
nEndPos = input.readLong(); g%[Ruugu  
} IH0^*f  
input.close(); nMbV{h ,  
} #5I "M WA  
catch(IOException e){e.printStackTrace ();} r#~6FpFVK^  
catch(Exception e){e.printStackTrace ();} `4p9K  
} vA{[F7  
u1kbWbHu(  
[E/3&3  
private void processErrorCode(int nErrorCode) Mo<p+*8u:  
{ ff hD+-gTU  
System.err.println("Error Code : " + nErrorCode); nz&JG~Qfm  
} Yr,1##u  
^~I  
5astv:p,P  
//停止文件下载 |3cR'|<Ual  
public void siteStop() )T+htD)  
{ J\0YL\jw1K  
bStop = true; y@z #Jw<  
for(int i=0;i<nStartPos.length;i++) ^b.J z}  
fileSplitterFetch.splitterStop(); y|mR'{$I  
gy[uq m_ T  
\ a<Ye T  
} 1wM p3  
} s`2o\]  
//负责部分文件的抓取 87/{\h  
**FileSplitterFetch.java ZqGq%8\.s  
*/ D.GSl  
package NetFox; u!S{[7 FY  
A| +{x4s`  
Aws TDM  
import java.io.*; _[7uLWyC9  
import java.net.*; Q&LkST-i  
Ek BM>*W  
mnia>; 0H  
public class FileSplitterFetch extends Thread { J{ Vl2P?@  
#75;%a8  
Mf63 59  
String sURL; //File URL tpctz~ .  
long nStartPos; //File Snippet Start Position *dl@)~i  
long nEndPos; //File Snippet End Position ,O+7nByi[V  
int nThreadID; //Thread's ID 1$W!<:uh  
boolean bDownOver = false; //Downing is over ~}116K  
boolean bStop = false; //Stop identical M/qiA.C@W  
FileAccessI fileAccessI = null; //File Access interface *$1)&2i  
5%$#3LT|  
3WY W])  
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException m}E$6E^~O  
{ koU.`l.  
this.sURL = sURL; '$VR_N\  
this.nStartPos = nStart; hg~fFj3ST  
this.nEndPos = nEnd; ]=3O,\  
nThreadID = id; J@fE" )  
fileAccessI = new FileAccessI(sName,nStartPos);//定位 V_QVLW  
} k|D!0^HE[  
.,,73"  
.wSAysiQ|P  
public void run() F*=RP$sj  
{ B+LNDnjO]  
while(nStartPos < nEndPos && !bStop) 1d"P) 3dQ  
{ Y4O L 82Y  
'9gI=/29D  
uwka 2aSS  
try{ |<0@RCgM  
URL url = new URL(sURL); KPhqD5, (  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); *GhRU5  
httpConnection.setRequestProperty("User-Agent","NetFox"); on\\;V_/Q  
String sProperty = "bytes="+nStartPos+"-"; >R<fm  
httpConnection.setRequestProperty("RANGE",sProperty); _<7FR:oBZ  
Utility.log(sProperty); #u$z-M !  
`vSsgG  
K/-D 5U  
InputStream input = httpConnection.getInputStream(); [1U_c*;i  
//logResponseHead(httpConnection); DvCt^O*  
a6d KQ3D  
I'C ,'  
byte[] b = new byte[1024]; lUEyo.xVt  
int nRead; 7w*&Yg]  
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) :S12=sFl$  
{ ?+\,a+46P_  
nStartPos += fileAccessI.write(b,0,nRead); \YS?}! 0  
//if(nThreadID == 1) nz\fN?q  
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); <GN?J.B  
} De_</1Au!2  
8rYK~Sz  
%-Z~f~<?  
Utility.log("Thread " + nThreadID + " is over!"); w$4Lu"N :  
bDownOver = true; ULjzhy+(8  
//nPos = fileAccessI.write (b,0,nRead); !Xi>{nV  
} d#Ajb  
catch(Exception e){e.printStackTrace ();} Kc0OLcu^d  
} vp@+wh]#  
} =*Xf(mhc  
M jTKM;  
Hi9z<l=$  
//打印回应的头信息 h'p0V@!N  
public void logResponseHead(HttpURLConnection con) ;>9pJ72r  
{ rE:>G]j6  
for(int i=1;;i++) ~~,<+X:  
{ : 4WbDeR  
String header=con.getHeaderFieldKey(i); Uj)]nJX  
if(header!=null) iurB8~Y  
//responseHeaders.put(header,httpConnection.getHeaderField(header)); }i:'f 2/  
Utility.log(header+" : "+con.getHeaderField(header)); VHCzlg  
else h6i{5\7.  
break; Gu).*cU  
} rR~X>+K  
} H)Ge#=;ckQ  
P;&p[[7  
F.D1;,x  
public void splitterStop() ud D[hPJd  
{ H@' @xHv  
bStop = true; ;[ueNP%*y|  
} I/jr` 3Mj  
XD}_9p  
Yur)_m  
} @/L. BfTz  
{2^ @jD  
+hgCk87%#  
/* VYo;[ue([  
**FileAccess.java dy?|Q33Y"  
*//文件访问(定位,写) XH$|DeAFM  
package NetFox; q&T'x> /  
import java.io.*; f*}E\,V"&  
CJ  
/ASI 0h  
public class FileAccessI implements Serializable{ Tpx,41(k  
98'XSL|  
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 #/<Y!qV&  
RandomAccessFile oSavedFile; 4 GW[GT  
long nPos; g}QTZT8  
I>Fh*2  
a&Du5(r;!  
public FileAccessI() throws IOException XF$]KA L0  
{ z %E!tB2o  
this("",0); C&N4<2b  
} s,H(m8#>  
C)p<M H<  
%5?-g[  
public FileAccessI(String sName,long nPos) throws IOException &W// Ox )f  
{ 4^_Au^8R(  
oSavedFile = new RandomAccessFile(sName,"rw"); 9?chCO(@  
this.nPos = nPos; .MARF  
oSavedFile.seek(nPos); _4B iF?1  
} ^) ^|;C\`  
W r7e_  
_kX/LR"L+  
public synchronized int write(byte[] b,int nStart,int nLen) 5XO'OSdYq  
{ eAKQR  
int n = -1; !&p:=}s  
try{ U] -@yx  
oSavedFile.write(b,nStart,nLen); f ?zK "  
n = nLen; W;]U P$5l  
} ./y[<e  
catch(IOException e) ]V^.!=gh$  
{ 6v O)s!b  
e.printStackTrace (); 6-14Htsk6  
} Ds,"E#?  
h=r< B\Pa  
P3ev 4DL  
return n; wf< `J/7u  
} Tc5OI'-V  
>@"3Q`  
IYg3ve`x  
} BBE1}V!u  
^^3va)1{!  
ZfCr"aL  
/* gdFoTcHgO|  
**SiteInfoBean.java NG!cEo:2aa  
*/ 3nC#$L-   
package NetFox; #r^@*<{^  
Yk@s"qm3  
::Q);  
public class SiteInfoBean { G|oB'~ {&  
&\ lS  
-L3 |9k  
private String sSiteURL; //Site's URL pXj/6+^  
private String sFilePath; //Saved File's Path Q*&aC|b&  
private String sFileName; //Saved File's Name ^'53]b:  
private int nSplitter; //Count of Splited Downloading File SOQ-D4q  
vp75u93  
2n;;Tso"  
public SiteInfoBean() \{=`F`oB=  
{//nSplitter的缺省值为5 m<,G:?RM  
//default value of nSplitter is 5 3et2\wOX1x  
this("","","",5); V&j.>Y  
} C\^<v&  
A.C278^O8  
\R>5F\ 0  
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) DEp%\sj?  
{ lJ]\  
sSiteURL= sURL; 4OZ5hH h  
sFilePath = sPath; IL2Gsj)M  
sFileName = sName; O-!fOdX8_k  
this.nSplitter = nSpiltter; 2|H91Y2  
9eN2)a/  
VO;UV$$  
} |]!Ky[P  
Pzm!`F^r}  
BOiz ~h6  
public String getSSiteURL() s!;VUr\  
{ w H_n$w  
return sSiteURL; iraRB~  
} -=t3O#  
1QF*e'  
.m]=JC5'  
public void setSSiteURL(String value) m`\i+  
{ PVS<QN%  
sSiteURL = value; ) 4L%zl7  
} V3A>Ag+^~  
*v nxP9<  
Rp`_Grcd  
public String getSFilePath() +`s&i%{1>  
{ h6T/0YhWLP  
return sFilePath; [' OCw {<  
} 1S[5#ewB;j  
Ux)p%-  
q4.dLU,1  
public void setSFilePath(String value) 'f?&EsIV?  
{ eFj6p<  
sFilePath = value; _z(5e  
} ?y*+^E0  
6`4W,  
Y zBA{FE  
public String getSFileName() /@:up+$  
{ nc\C 4g  
return sFileName; ? __aVQ7  
} d7_g u  
0n<(*bfW  
w^due P7J  
public void setSFileName(String value) $uFh$f  
{ Q{l*62Bx  
sFileName = value; v<7Gln  
} Ub'%pU  
^`jZKh8)h  
;&W;  
public int getNSplitter() lR@i`)'?U  
{ $nfBv f  
return nSplitter; ^L8Wn6s'  
} <h@z=ijN  
l\=-+'Y  
NHFEr  
public void setNSplitter(int nCount) Bd[L6J)  
{ a:-)+sgHw  
nSplitter = nCount; aZawBU.:  
} yA?ENAM  
} NO+ 55n  
{n'qKur xY  
n(Q\' ,C  
/* sR>`QIi(a  
**Utility.java m,@1LwBH  
*/ F[7Kw"~J  
package NetFox; ( *9Ip  
M)`HK .  
}l}yn@hYC  
public class Utility { W) 33;E/}  
0tW<LR-}E  
?}=-eJ(7e  
public Utility() dDqr B-G  
{ *1Ut}  
CCW%G,$U9  
)@<HCRQ'q  
} pyg!rf-  
YH'$_,8peM  
//线程睡眠 0HHui7Yy>  
public static void sleep(int nSecond) uOG-IHuF  
{ P>{US1t  
try{ 42V,PH6o  
Thread.sleep(nSecond); X/E7o92\  
} `sk!C7%  
catch(Exception e) 3qAwBVWa  
{ {*?sVAvj  
e.printStackTrace (); y^mWG1"O  
} V\@jC\-5Vt  
} N ;Z`%&  
*?^Z)C>  
//日志 Sg.+`xww3  
public static void log(String sMsg) e$Xq    
{ C5PmLiOHY>  
System.err.println(sMsg); 4-7kS85  
} |RR%bQ^{  
1jH7<%y  
6WE&((r ^  
public static void log(int sMsg) ^s^ JzFw  
{ 2gd<8a''  
System.err.println(sMsg); 861i3OXVE>  
} ;m@1Ec@* p  
} Qy=HrL]x  
kgbobolA  
Y{k>*: Ax_  
/* HYjMNj0  
**TestMethod.java s;fVnaqG:  
*/ eeW' [  
package NetFox; L bJtpwz>z  
)\T@W  
$ ^W-Wmsz  
public class TestMethod { F . K2  
5l41Q  
On{~St'V  
public TestMethod() gohAp  
{ ///xx/weblogic60b2_win.exe ]ZzoJ7lr  
try{ $?FS00p*|X  
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); AVXX\n\_  
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); `y\*m]:  
SiteFileFetch fileFetch = new SiteFileFetch(bean); ds*m6#1b  
fileFetch.start(); O^.%C`*  
} a'@-"qk  
catch(Exception e){e.printStackTrace ();} $uEJn&n7}  
Xw7{R  
'oz hz2s  
} ^ckj3Y#;  
Yv)Bj  
)t|^Nuj8  
public static void main(String[] args) iD>G!\&  
{ T)WZ_bR  
new TestMethod(); Y]C; T  
} hc-lzYS  
} Xzl KP;r0  
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