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http断点续传简单实现(java)

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/* D |=L)\  
**SiteFileFetch.java AhkDLm+  
*/ )PkW,214#  
package NetFox; @?jtB  
import java.io.*; ~0h@p4  
import java.net.*; 2OpkRFFa  
Be9,m!on  
xs&xcR R"  
public class SiteFileFetch extends Thread { q6ZewuV.  
(I`lv=R"j  
`v-O 4Pk  
SiteInfoBean siteInfoBean = null; //文件信息Bean :`4F0  
long[] nStartPos; //开始位置 a`8]TD  
long[] nEndPos; //结束位置 &Yo|Pj  
FileSplitterFetch[] fileSplitterFetch; //子线程对象 S.{   
long nFileLength; //文件长度 yh/JHo;  
boolean bFirst = true; //是否第一次取文件 UM`{V5NG#  
boolean bStop = false; //停止标志 ~<-mxOe  
File tmpFile; //文件下载的临时信息 =~"X/ >'  
DataOutputStream output; //输出到文件的输出流 B&7NF}CF2  
dVk(R9 8  
//负责整个文件的抓取,控制内部线程(FileSplitterFetch类) QJ(5o7Tfn  
public SiteFileFetch(SiteInfoBean bean) throws IOException f5p/cUzX  
{ 61b*uoq0w?  
siteInfoBean = bean; 6i%6u=um3  
//tmpFile = File.createTempFile ("zhong","1111",new File(bean.getSFilePath())); , @!X! L  
tmpFile = new File(bean.getSFilePath()+File.separator + bean.getSFileName()+".info"); VR .t  
if(tmpFile.exists ()) XUKlgl!+.  
{ 9]{va"pe7  
bFirst = false; ( et W4p  
read_nPos(); 6O,:I  
} in5e *  
else l p(D@FT  
{ -Lq2K3JHyn  
nStartPos = new long[bean.getNSplitter()]; V1,/qd_  
nEndPos = new long[bean.getNSplitter()]; rHM^_sYRb  
} & Zn`2%  
o='A1P  
fL# r@TB-s  
YQ.ci4.f  
} e(N},s:_  
BU4IN$d0Po  
xticC>  
public void run() vcsSi%M\U  
{ (w{T[~6  
//获得文件长度 j!y9E~Zz  
//分割文件 :p,|6~b$  
//实例FileSplitterFetch IuT)?S7O*k  
//启动FileSplitterFetch线程 ;c>"gW8  
//等待子线程返回 SO.u0!  
try{ j RcE241  
if(bFirst) E#_2t)20  
{ x=IZ0@p  
nFileLength = getFileSize(); d:w/{m% #  
if(nFileLength == -1) wJ pb$;  
{ @HiGc^ X(  
System.err.println("File Length is not known!"); U<Tv<7`  
} [*Ai@:F  
else if(nFileLength == -2) ?AD- n6  
{ nGe4IY\-w  
System.err.println("File is not access!"); (# mvDz  
} E N%{ $  
else ;[UI ]?A%  
{ e[?,'Mp9  
for(int i=0;i<nStartPos.length;i++) h]L.6G|hEN  
{ BWQ`8  
nStartPos = (long)(i*(nFileLength/nStartPos.length)); SMIDW}U2S  
} m[^ )Q9o}  
for(int i=0;i<nEndPos.length-1;i++) .d}yQ#5z  
{ 4sntSlz)~k  
nEndPos = nStartPos[i+1]; 7Mq{Py1  
} Il9xNVos#  
nEndPos[nEndPos.length-1] = nFileLength; Y,GlAr s4  
} CQNMCYjg(R  
} <tBT?#C9+  
vPGUE`!D+  
_@y uaMoW=  
//启动子线程 ||Owdw|{  
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; !yPy@eP~  
for(int i=0;i<nStartPos.length;i++) OdZ/\_Z  
{ e"wz b< b  
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), <" nWGF4d  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), b r Iz8]  
nStartPos,nEndPos,i); #*/nUbsg  
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); ;4ybkOD  
fileSplitterFetch.start(); Im\ ~x~{  
} z,$uIv}'@  
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), S6(48/  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1);  @--"u_[  
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", |'1.a jxw  
nEndPos = " + nFileLength); v@OELJX  
// fileSplitterFetch[nPos.length-1].start(); 7Y[ q)lv  
]W$G!(3A  
D4@?>ek6U  
//等待子线程结束 rh1PpsSc  
//int count = 0; N2U&TCc  
//是否结束while循环 \1gAWUt('  
boolean breakWhile = false; hHTt-x#  
-&`_bf%M  
E b:iym0  
while(!bStop) qbsod  
{ K<:%ofB"S  
write_nPos(); c5$DHT @N"  
Utility.sleep(500); HEbL'fw^s  
breakWhile = true; >!@D^3PPA  
p<H_]|7$7U  
LwRzzgt  
for(int i=0;i<nStartPos.length;i++) x}pH'S7  
{ G#e]J;   
if(!fileSplitterFetch.bDownOver) \ t1#5  
{ kJJiDDL0;*  
breakWhile = false; XJPIAN~l  
break; .pWRV<25  
} &hkD"GGe  
} .tLRY  
if(breakWhile) 7Z`4Kdh .  
break; a'|]_`36x  
&Pm@+ML*x  
P$Vh{]4i{  
//count++; fsPNxy"_  
//if(count>4) ^8~TsK~  
// siteStop(); 8 <;.[l  
} ?i0+h7 =6  
DJgM>&Y6,  
`Wjq$*  
System.err.println("文件下载结束!"); rgCC3TX  
} /klo),|&  
catch(Exception e){e.printStackTrace ();} zO\_^A|8H  
} Bj2iYk_cLa  
!{CIP`P1  
0J'Cx&Rg  
//获得文件长度 Xe\}(O  
public long getFileSize() W|@SXO)DY  
{ 72xf| s=  
int nFileLength = -1; g]HWaFjc5  
try{ S+[,\>pY  
URL url = new URL(siteInfoBean.getSSiteURL()); ]^.`}Y=`g  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); {$[0YRNk u  
httpConnection.setRequestProperty("User-Agent","NetFox"); Bf00&PE;  
 2=;ZJ  
hfLe<,  
int responseCode=httpConnection.getResponseCode(); sj&(O@~R  
if(responseCode>=400) r+[g.`  
{ K/C}  
processErrorCode(responseCode); okRt^qe  
return -2; //-2 represent access is error &$CyT6mb^  
} ~s4JGV~R  
 EH2):  
lshSRir  
String sHeader; ym6Emf]  
sq#C|v/  
U:$z lfV  
for(int i=1;;i++) n8!|}J  
{ )E=B;.FH  
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); 2i!R>`  
//Utility.log(in.readLine()); ~m=Z>4M  
sHeader=httpConnection.getHeaderFieldKey(i); I:=!,4S;  
if(sHeader!=null) ]wV\=m?z&  
{ 2N &B  
if(sHeader.equals("Content-Length")) {`2 0'  
{ V?JmIor  
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); Pfvb?Hy  
break; uv$5MwKU  
} $aTo9{M^  
} {)r[?%FMgV  
else "[["naa  
break; 9mMQ  
} B &Z0ZWx  
} =r]_$r%gR  
catch(IOException e){e.printStackTrace ();} oSMIWwg7G  
catch(Exception e){e.printStackTrace ();} F'{T[MA  
ZT&[:>upR  
Uhh[le2 %  
Utility.log(nFileLength); j^ 8Hjg  
7SkW!5  
N/{=j  
return nFileLength; ?cz7s28a  
} rS\mFt X  
8sDw:wTC  
:+_H%4+  
//保存下载信息(文件指针位置) Z] cFbl\ma  
private void write_nPos() ]OKKR/:  
{ J^` pE^S  
try{ )0 6. dZq\  
output = new DataOutputStream(new FileOutputStream(tmpFile)); L~|_)4  
output.writeInt(nStartPos.length); .ejC#vB{KM  
for(int i=0;i<nStartPos.length;i++) t9W*N\  
{ fF/;BSq'  
// output.writeLong(nPos); 8j&1qJx)  
output.writeLong(fileSplitterFetch.nStartPos); U .^%7.  
output.writeLong(fileSplitterFetch.nEndPos); js)E:+{A,  
} '2|mg<Ft  
output.close(); uh)f/)6  
} 96F+I!qC  
catch(IOException e){e.printStackTrace ();} ^JIs:\ g<<  
catch(Exception e){e.printStackTrace ();} QB* AQ5-  
} dXt@x8E  
yyVJb3n5:!  
{2g?+8L$Z  
//读取保存的下载信息(文件指针位置) S,+|A)\#  
private void read_nPos() * e,8o2C$  
{ 9WoTo ,q  
try{ 2U+wiE|  
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); ,5*<C'9  
int nCount = input.readInt(); R<h:>.M  
nStartPos = new long[nCount]; "wV7PSbM  
nEndPos = new long[nCount]; jw2hB[WR  
for(int i=0;i<nStartPos.length;i++) S|RUc}(  
{ Jn0L_@  
nStartPos = input.readLong(); Fok`-U  
nEndPos = input.readLong(); LwQYO'X  
} `$;%%/tx  
input.close(); MGKSaP;x  
} g( eA?  
catch(IOException e){e.printStackTrace ();} S^e e<%-  
catch(Exception e){e.printStackTrace ();} #{bT=:3a  
} +>mU4Fwp  
Z79Y$d>G<E  
%. IW H9P7  
private void processErrorCode(int nErrorCode) |oOA;JC)(  
{ pi*?fUg!W  
System.err.println("Error Code : " + nErrorCode); F*B^#AZg  
} G"<} s mB  
~|wh/]{b9  
` NvJ  
//停止文件下载 %8% 0l*n'  
public void siteStop() J]*?_>"#8  
{ ;ahI}}  
bStop = true; JHVesX  
for(int i=0;i<nStartPos.length;i++) olDzmy(=W*  
fileSplitterFetch.splitterStop();  #|l#  
g31\7\)Ir  
6O'B:5~[2  
} pEGHW;  
} ^zS|O]Tx  
//负责部分文件的抓取 Z oKXao  
**FileSplitterFetch.java Bd13p_V"6  
*/ j=b-Y  
package NetFox; #5IfF~* i  
?B4X&xf.D  
Fmrl*tr  
import java.io.*; H]f8W]"c[  
import java.net.*; M059"X="  
-S}^b6WL  
Q S.w#"X[  
public class FileSplitterFetch extends Thread { Z2\Xe~{  
iJ`v3PP  
llBW*4'  
String sURL; //File URL 24_/JDz  
long nStartPos; //File Snippet Start Position tj!~7lo  
long nEndPos; //File Snippet End Position _ <pO<S  
int nThreadID; //Thread's ID M*jn8OE  
boolean bDownOver = false; //Downing is over +@C|u'  
boolean bStop = false; //Stop identical !='&#@7u  
FileAccessI fileAccessI = null; //File Access interface Xu5^ly8p9q  
?[Qxq34  
ZEU/6.  
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException ^5gB?V,  
{ =g^JJpS  
this.sURL = sURL; {B6tGLt#bf  
this.nStartPos = nStart; `OyYo^+D|.  
this.nEndPos = nEnd; :,dO7dJi  
nThreadID = id; ApAHa]Ccp  
fileAccessI = new FileAccessI(sName,nStartPos);//定位 .[:*bo3  
} FHu+dZ  
=_dqoAF  
%MUwd@,  
public void run() L{i|OK^e  
{ Rlf#)4  
while(nStartPos < nEndPos && !bStop) ZzO.s$  
{ \>XkK<ye  
lW YgIpw  
-jsk-,  
try{ Jyu*{  
URL url = new URL(sURL); {[.<BU-  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); wS1zd?  
httpConnection.setRequestProperty("User-Agent","NetFox"); a<`s'N1G  
String sProperty = "bytes="+nStartPos+"-"; k39;7J  
httpConnection.setRequestProperty("RANGE",sProperty); &!FWo@  
Utility.log(sProperty); s3l:ST  
1{X ;&y  
zINziAp{  
InputStream input = httpConnection.getInputStream(); {B lM<  
//logResponseHead(httpConnection); G^Yg[*bJ^$  
&ffd#2f`@  
q--;5"=S  
byte[] b = new byte[1024]; 3DO ^vV  
int nRead; Bl)DuCV  
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) Tj*Vk $}0  
{ t1tZ:4  
nStartPos += fileAccessI.write(b,0,nRead); ;7 Y4 v`m  
//if(nThreadID == 1) dg]: JU  
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); UDz#?ZWnd  
} [8Zvs=1  
S+(-k0  
Od:, r  
Utility.log("Thread " + nThreadID + " is over!"); #\fxU:z~r  
bDownOver = true; v81H!c.*  
//nPos = fileAccessI.write (b,0,nRead); n$T'gX#5  
} <U() *0  
catch(Exception e){e.printStackTrace ();} xT$9M"  
} 42: 6=\  
} ;4 ON  
gNG_,+=!  
]RJcY1  
//打印回应的头信息 r|tTDKGQ  
public void logResponseHead(HttpURLConnection con) XZFM|=%X  
{ _7"G&nZ0  
for(int i=1;;i++) Pb^Mc <j  
{ ("L&iu\`@  
String header=con.getHeaderFieldKey(i); Bzw!,(u/ "  
if(header!=null) 4U;6 2 jq  
//responseHeaders.put(header,httpConnection.getHeaderField(header)); xui.63/  
Utility.log(header+" : "+con.getHeaderField(header)); 0 ))W [  
else +MfdZD  
break; Sc zYL?w^  
} GwoN=  
} le-Q&*  
24 i00s|#  
IPhV|7  
public void splitterStop() 5h2@n0  
{ _#/zH~V%  
bStop = true; 2Y@:Vgg  
} >f$>Odqe  
y J&`@gB  
p|z\L}0  
} ^sp+ sr :  
M6P`~emX2  
@;we4G5  
/* Sp=6%3fZ]m  
**FileAccess.java [l2ds:  
*//文件访问(定位,写) gz?]]-H  
package NetFox; ?p8(Uc#73  
import java.io.*; 67/&.d!  
OA_Bz"  
=hO0 @w  
public class FileAccessI implements Serializable{ zMkjdjb  
l25E!E-'b  
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 =;9*gDfD  
RandomAccessFile oSavedFile; yqm^4)Dp  
long nPos; <I{)p;u1  
aD1G\*AFJ  
.*N,x0 B(  
public FileAccessI() throws IOException E  K)7g~  
{ VE<&0d<  
this("",0); m\88Etl@  
} o#-K,|-  
/^kZ}}9baU  
\WnI&nu  
public FileAccessI(String sName,long nPos) throws IOException J<<0U;  
{ <= xmJx-V  
oSavedFile = new RandomAccessFile(sName,"rw"); +|N!(H  
this.nPos = nPos; ,[lS)`G  
oSavedFile.seek(nPos); ix<sorR H  
} k#I4^  
S&A, Q'  
Xq9n-;%zL  
public synchronized int write(byte[] b,int nStart,int nLen) 4{h?!Z*  
{ <303PPX^6  
int n = -1; d+_wN2  
try{ s 9,?"\0Zm  
oSavedFile.write(b,nStart,nLen); @"9^U_Qf1z  
n = nLen; Efm37Kv5l  
} Q3M;'m  
catch(IOException e) "0F =txduS  
{ }2^_Gaj  
e.printStackTrace (); OA\2ja~+  
} $DmWK_A  
<Q06<{]R8  
8$:4~:]/  
return n; /Ot=GhN]  
} u.t(78N  
OKU9v{  
dc MWCK  
} #HD$=ECcw  
x:`]uOp  
sglYT!O  
/* ;IC:]Zu  
**SiteInfoBean.java HB+\2jEE  
*/ ;O*y$|+PA  
package NetFox; -0 [^w  
E>tlY&0[$  
2,c{Z$\kn  
public class SiteInfoBean { #<X+)B6t  
U5; D'G  
w`(EW>i  
private String sSiteURL; //Site's URL FnN@W^/z  
private String sFilePath; //Saved File's Path 85rXm*Df  
private String sFileName; //Saved File's Name qNP&f 8fH  
private int nSplitter; //Count of Splited Downloading File &D "$N"  
#2thg{5  
Vx5ioA]{  
public SiteInfoBean() _cqB p7  
{//nSplitter的缺省值为5 1us-ootsjP  
//default value of nSplitter is 5 yIBT*,4  
this("","","",5); c}a.  
} *Z! #6(G  
'k=GSb  
A2{u("^[6  
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) #>+O=YO  
{ b{|Ha3;w  
sSiteURL= sURL; Yyq:5V!  
sFilePath = sPath; S3V3<4CB  
sFileName = sName; w /$4 Rv+S  
this.nSplitter = nSpiltter; p/|]])2  
ozZW7dveU  
$=7[.z&  
} 'u }|~u?m  
;iJ*.wVq  
5CZii=@  
public String getSSiteURL() e"u=4nk  
{ WQ/H8rOs  
return sSiteURL; {=W TAgP  
} &?m|PK)I  
9NTBdo%u  
COe"te  
public void setSSiteURL(String value) C%ibIcm y  
{ eRkvNI  
sSiteURL = value; -~O7.E(ok  
} o}&TFhT  
gTE/g'3  
kB-%T66\  
public String getSFilePath() z;6 Tp  
{ @^8tk3$ Y  
return sFilePath; bmT_tNz  
} X}.y-X#v5J  
hqW4.|&\c  
 VP H  
public void setSFilePath(String value) 8<UD#i@:C  
{ gPO,Z  
sFilePath = value; JivkY"= F  
}  7e\g  
z1t YD  
0|g|k7c{rF  
public String getSFileName() GAONgz|ZI  
{ FA-"" ]  
return sFileName; ZUJ !  
} t]|WRQvy8  
1Zc1CUMG  
t#tAvwFM8  
public void setSFileName(String value) iR;Sd >)  
{ 6/`$Y!.ub  
sFileName = value; rQ -pD  
} (| DmYn!  
S '>(4a  
+cQGX5 K  
public int getNSplitter() iHoQNog-!  
{ t sdkpt  
return nSplitter;  ]~g6#@l  
} J%d\ 7  
BdcTKC  
%n-:mSus  
public void setNSplitter(int nCount) C$o#zu q -  
{ ydo"H9NOS  
nSplitter = nCount; qgd#BJ=  
} R)% Jr.U  
} +]^6&MqO  
Pt~mpRl H  
s@^ (1g[w`  
/* f/t1@d!  
**Utility.java 2P9gS[Ub  
*/ &WN#HI."]  
package NetFox; lhsd 39NM  
c,a+u  
0j*-ZvE)30  
public class Utility { N*6Y5[g!\  
bF:]MB^VK  
|=H*" (  
public Utility() o@TxDG  
{ t2Dx$vT*&  
b0 ))->&2  
B. Rc s  
} p!^.;c  
2 2K:[K  
//线程睡眠  DJ?kQ  
public static void sleep(int nSecond) e573UB  
{ ft oz0Vb  
try{ `9QvokD  
Thread.sleep(nSecond); ad^7t<a}<  
} V?U->0>Z4  
catch(Exception e) "Sp+Q&2U  
{ | k"?I  
e.printStackTrace (); k,o|"9H  
} CAg\-*P|  
} e%#(:L  
6x%uWZa'  
//日志 bp G`,[  
public static void log(String sMsg) b#%s!  
{ ~e<l`rg#  
System.err.println(sMsg); 7kmU/(8  
} $Lpt2:.((  
Bbuy y  
lWj{pyZ  
public static void log(int sMsg) o~7~S  
{ (=:9pbP  
System.err.println(sMsg); jUjgxP*7m  
} t}LV[bj1u  
} 2\h]*x% :  
~nk{\ rWO  
v;.7-9c*  
/* o.yuz+  
**TestMethod.java p%) 1(R8qM  
*/ AF5.)Y@.  
package NetFox; GKf,1kns  
RRh0G>*  
69{^Vfd;Y  
public class TestMethod { #$p&J1   
p9w<|ZQ]:  
llVm[7  
public TestMethod() >?iL_YTX  
{ ///xx/weblogic60b2_win.exe emp*j@9  
try{ J#DYZ>}Y  
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); 6XyhOs%/  
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); }RX[J0Prq~  
SiteFileFetch fileFetch = new SiteFileFetch(bean); L&3Ak}sh  
fileFetch.start(); &Rw4ub3  
} p/jC}[$v  
catch(Exception e){e.printStackTrace ();} !yAlb#yu  
H8d%_jCr  
*FoH '\=  
} ~"eos~AuW  
ZMO7 o 1"  
JWhi*je  
public static void main(String[] args) TR:V7 d  
{ 9W3zcL8  
new TestMethod(); wc7gOrPpm  
} 7J@iJW],,  
} u 0M[B7Q  
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