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http断点续传简单实现(java)

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/* v50=D/&w  
**SiteFileFetch.java JVU:`BH  
*/ m39 `f,M  
package NetFox; +DksWb D  
import java.io.*; 'AHI;Z~Gk  
import java.net.*; Uq7 y4zJ  
m"NZ;*d'  
[CJ&Yz Ji  
public class SiteFileFetch extends Thread { 8hGp?Ihu  
/9;)zI  
x# 0(CcKK  
SiteInfoBean siteInfoBean = null; //文件信息Bean ?~;G)5  
long[] nStartPos; //开始位置 uEH&]M>d_  
long[] nEndPos; //结束位置 N^B YNqr  
FileSplitterFetch[] fileSplitterFetch; //子线程对象 4$@)yZ  
long nFileLength; //文件长度 8I3"68c_a  
boolean bFirst = true; //是否第一次取文件 @MS;qoc  
boolean bStop = false; //停止标志 3S ,D~L^  
File tmpFile; //文件下载的临时信息 xn}sh[<:P  
DataOutputStream output; //输出到文件的输出流 Kr!8H/Z  
IZoa7S&t  
//负责整个文件的抓取,控制内部线程(FileSplitterFetch类) ,vl][MhM  
public SiteFileFetch(SiteInfoBean bean) throws IOException )k{zRq:d  
{ 5Jlz$]f  
siteInfoBean = bean; yuWoz*:t  
//tmpFile = File.createTempFile ("zhong","1111",new File(bean.getSFilePath())); a=T_I1  
tmpFile = new File(bean.getSFilePath()+File.separator + bean.getSFileName()+".info"); TIYI\/a\;  
if(tmpFile.exists ()) P'xq+Q  
{ UF3WpA  
bFirst = false; *^ g7kCe(  
read_nPos(); TeSF  
} @.6l^"L  
else <p;cR` %uE  
{ !7]4sXL{  
nStartPos = new long[bean.getNSplitter()]; WgF Xv@Jjt  
nEndPos = new long[bean.getNSplitter()]; e?rp$kq7  
} aOFF"(]Cl  
Yh\ } i  
n(\5Z&  
6lpfk&  
} Pfj{TT.#L  
sg RY`U.C  
b`)^Ao:  
public void run() Wt*&_+ae  
{ o|F RG{TJ  
//获得文件长度 ?aR)dQ  
//分割文件 sN.h>bd  
//实例FileSplitterFetch 7+QD=j-  
//启动FileSplitterFetch线程 PBc.}TSGj  
//等待子线程返回 zZE 2%fqM  
try{ BuII|j  
if(bFirst) 4RTuy+ M  
{ </(bwc~2  
nFileLength = getFileSize(); C%}}~Y  
if(nFileLength == -1) ?]+{2&&$  
{ ^kA^> vi  
System.err.println("File Length is not known!"); ~OO&%\$k  
} ppH5>Y 6c  
else if(nFileLength == -2) K"B2 SsC  
{  *(5y;1KU  
System.err.println("File is not access!"); {fW(e?8)  
} rw/WD(  
else m08:EX P  
{ L8sHG$[  
for(int i=0;i<nStartPos.length;i++) /ZlPEs)  
{ Exd$v"s Y  
nStartPos = (long)(i*(nFileLength/nStartPos.length)); )D?\ru H  
} 'S]7:/CI  
for(int i=0;i<nEndPos.length-1;i++) R%B"Gtl)  
{ %5.aC|^}  
nEndPos = nStartPos[i+1]; oU[Ba8qh  
} p w(eWP  
nEndPos[nEndPos.length-1] = nFileLength; X=$WsfN.h  
} S3EM6`q'  
} t-7^deG'/n  
KKpO<TO  
e%. Xya#\  
//启动子线程 F/GfEMSE  
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; #'m&<g,  
for(int i=0;i<nStartPos.length;i++) G&8)5d[  
{ :KY920/,  
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), VQA}!p  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), CZaUrr  
nStartPos,nEndPos,i); ]gI>ay"\QA  
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); pt[H5  
fileSplitterFetch.start(); <5rs~  
} =xz Dpn>f  
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), z/09~Hc  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); DL0jA/f  
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", )9LlM2+y  
nEndPos = " + nFileLength); c|?0iN  
// fileSplitterFetch[nPos.length-1].start(); F|.,lb |L  
GiI|6z!  
IoUQ~JviA  
//等待子线程结束 6b& <5,=d:  
//int count = 0; wXdtY  
//是否结束while循环 Hjl{M>z  
boolean breakWhile = false; {@j0?s  
N0A PX4j  
. !gkJ  
while(!bStop) LS1r}cl  
{ 5cLq6[uO  
write_nPos(); /O@'XWW  
Utility.sleep(500); !J<}=G5  
breakWhile = true; {c5%.<O  
m?LnO5Vs  
Gd^K,3:. T  
for(int i=0;i<nStartPos.length;i++) LvP{"K;   
{ |KSd@   
if(!fileSplitterFetch.bDownOver) Fh  t$7V  
{ 4-l G{I_S:  
breakWhile = false; 8w,U[aJm  
break; $r0~& $T&  
} x\HHu]  
} LObS 7U  
if(breakWhile) Bqo8G->  
break; rzmd`)g  
(pY'v /a-  
FtBYPSGz  
//count++; "{a-I=s\C  
//if(count>4) Vy*&po[   
// siteStop(); Ph[P$: 9  
} :0K[fBa  
fa#xEWaFr  
s-^B)0T!  
System.err.println("文件下载结束!"); 0Vu&UD  
} /JaCbT?*T  
catch(Exception e){e.printStackTrace ();} BGAqg=nDV  
} QEd>T"@g  
'C=8.P?  
k&Z3v.  
//获得文件长度 }9Yd[`  
public long getFileSize() QP+zGXd}(  
{ 9G)Sjn`AQ  
int nFileLength = -1; BLc&q)  
try{ GL4-v[]6I  
URL url = new URL(siteInfoBean.getSSiteURL()); a`SQcNBf*  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); S 6e<2G=O  
httpConnection.setRequestProperty("User-Agent","NetFox"); o80?B~o  
+RIG8w]  
ziFg+i%s  
int responseCode=httpConnection.getResponseCode(); B^4D`0G[4  
if(responseCode>=400) Yt^<^l77D  
{ ym*,X@Qg^  
processErrorCode(responseCode); GE+ %V7  
return -2; //-2 represent access is error $@ /K/"  
} b-sbRR  
4=]CAO=O  
Z0yy<9q]2  
String sHeader; ?_Sf  
["FC   
53y,eLf  
for(int i=1;;i++) \W^Mo>l  
{ <sXmk{  
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); w&6c`az8  
//Utility.log(in.readLine()); EBF608nWfW  
sHeader=httpConnection.getHeaderFieldKey(i); $i# 1<Qj  
if(sHeader!=null) | CNsa  
{ k+*DPo@)  
if(sHeader.equals("Content-Length")) V*an0@  
{ SSi-Z  
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); ~(%TQY5  
break; 'G3;!xk$  
} :\ %.x3T'  
} 6U{&`8C  
else f? sW^ d;  
break; 4[@`j{  
} j 8lWra\y  
} -b1VY4m-  
catch(IOException e){e.printStackTrace ();} 6.]x@=Wm  
catch(Exception e){e.printStackTrace ();} kbij Zj{  
`1I@tz|  
&[]0yNG  
Utility.log(nFileLength); Q/e$Ttt4J  
OKDBzl  
Vq7L:,N9  
return nFileLength; 9 C-!I,  
} -8- BVU  
V wj^h  
Qg dHIMY  
//保存下载信息(文件指针位置) YHoj^=/b  
private void write_nPos() EH;w <LvT  
{ \Qp #utC0s  
try{ x)'4u6;d  
output = new DataOutputStream(new FileOutputStream(tmpFile)); YuO-a$BP  
output.writeInt(nStartPos.length); JXR_klx  
for(int i=0;i<nStartPos.length;i++) g.CUo:c  
{ A]VcQ_e  
// output.writeLong(nPos); C)2Waj}  
output.writeLong(fileSplitterFetch.nStartPos); xRZ9.Agv_  
output.writeLong(fileSplitterFetch.nEndPos); :5/P{Co (  
} k!/"J ;  
output.close(); Z,'#=K  
} 8"2 Y$*)(  
catch(IOException e){e.printStackTrace ();} 6#NptXB  
catch(Exception e){e.printStackTrace ();} b >R/=tx  
} !L3M\Q0  
zu6Y*{$>g  
 T~I5W=y  
//读取保存的下载信息(文件指针位置) zB6u%uWR  
private void read_nPos() '\[o>n2  
{ kNX"Vo]1  
try{ ^X$k<nA;  
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); igNZe."V  
int nCount = input.readInt(); 2i+'?.P  
nStartPos = new long[nCount]; #q2 cVN1  
nEndPos = new long[nCount]; YyR)2j1O  
for(int i=0;i<nStartPos.length;i++) Aj`zT'  
{ 4z~ fn9g  
nStartPos = input.readLong(); INQ0h`T  
nEndPos = input.readLong(); >Le L%$  
} _c}@Fi+E  
input.close(); R-Y|;  
} ;aA,H&   
catch(IOException e){e.printStackTrace ();} ZVo%ssVt  
catch(Exception e){e.printStackTrace ();} - i``yf?P  
} "zSi9]j  
x,W)qv  
uus}NZ:*l  
private void processErrorCode(int nErrorCode) L,Jl# S  
{ /I2RU2|B  
System.err.println("Error Code : " + nErrorCode); ~.4-\M6[  
} TV$Pl[m   
(<?6X9F:N  
m>4jRr6sF  
//停止文件下载 Y)@mL~){  
public void siteStop() :Mz$~o<  
{ S1Q2<<[  
bStop = true; \79KU   
for(int i=0;i<nStartPos.length;i++) R/)cEvB-0  
fileSplitterFetch.splitterStop(); 'I|A*rO  
b2OVg +3  
q'kZ3 G   
} CJA5w[m  
} cr!6qv1  
//负责部分文件的抓取 =$`xis\  
**FileSplitterFetch.java _akC^h T  
*/ J 00<NRxj"  
package NetFox; N>z<v\`  
Do@:|n  
 SJY<#_b  
import java.io.*; i~\fpay  
import java.net.*; -uZ bVd  
J[ 9yQ  
$~UQKv>  
public class FileSplitterFetch extends Thread { %x_c2  
%GUu{n<6  
0T,Qn{  
String sURL; //File URL :>gzWVE<  
long nStartPos; //File Snippet Start Position dI!x Ai  
long nEndPos; //File Snippet End Position @=o1q=5@8  
int nThreadID; //Thread's ID &IGTCTBP  
boolean bDownOver = false; //Downing is over DXPiC[g]  
boolean bStop = false; //Stop identical ,: X+NQ  
FileAccessI fileAccessI = null; //File Access interface _RG!lmJV  
eto3dJ!R  
VO ^ [7Y  
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException ~YO-GX(  
{ =|IB=  
this.sURL = sURL; g+8j$w}  
this.nStartPos = nStart; HA%% WSuf  
this.nEndPos = nEnd; mx@F^  
nThreadID = id; y=y=W5#;77  
fileAccessI = new FileAccessI(sName,nStartPos);//定位 FoM4QO  
} \tFg10  
mQt';|X@  
%1ofu,%  
public void run() h4C DZ  
{ }>vf(9sF`  
while(nStartPos < nEndPos && !bStop) wD>tR SW  
{ ,<$6-3sC-  
;2"#X2B  
A:Z$i5%'  
try{ t59" [kQ  
URL url = new URL(sURL); @ mm*S:Gt#  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 8%s ^>.rG  
httpConnection.setRequestProperty("User-Agent","NetFox"); eCB(!Y|  
String sProperty = "bytes="+nStartPos+"-"; B<c7&!B  
httpConnection.setRequestProperty("RANGE",sProperty); 2 g"_ *[  
Utility.log(sProperty); 910Ym!\{:  
-|^}~yOx0=  
b#0y-bR  
InputStream input = httpConnection.getInputStream(); j`I[M6Qxh  
//logResponseHead(httpConnection); 7sECbbJT  
5Cxh >,k  
"Y@rNmBj  
byte[] b = new byte[1024]; BcaMeb-Z  
int nRead; kR%bdN  
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) WrhC q6  
{ xz#;F ,`ZR  
nStartPos += fileAccessI.write(b,0,nRead); #*uSYGdc  
//if(nThreadID == 1) LO@.aJpp  
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); %Kd&A*  
} ,]@K6  
.$b]rx7$ ~  
e*_8B2da  
Utility.log("Thread " + nThreadID + " is over!"); lcgT9 m#  
bDownOver = true; 96;17h$  
//nPos = fileAccessI.write (b,0,nRead); xQ4D| &  
} Tj@}O:q7:  
catch(Exception e){e.printStackTrace ();} GF5WR e(E  
} !=C4=xv  
} dw,Nlf~*0  
2SU G/-P#  
Q\G8R^9j p  
//打印回应的头信息 f!;i$Oif  
public void logResponseHead(HttpURLConnection con) BQWEC,*N  
{ !}wJ+R ^2  
for(int i=1;;i++) "sF&WuW|  
{ d;&'uiS  
String header=con.getHeaderFieldKey(i); g~_cYy  
if(header!=null) evf){XhT;n  
//responseHeaders.put(header,httpConnection.getHeaderField(header)); Kx9Cx 5B  
Utility.log(header+" : "+con.getHeaderField(header)); <mlQn?u  
else ]bO {001y,  
break; 9_'xq.uP  
} b u%p,u!  
} QC0^G,9.  
T[M?:~  
nt\6o?W  
public void splitterStop() "~x\bSY  
{ uEQH6~\{Nl  
bStop = true; I@P[}XS  
} kzr9-$eb  
wVk2Fr(  
]k Ls2? \  
} 0-"ps]X  
G1M}g8 ]h  
=O~1L m;  
/* 2%0z PflT  
**FileAccess.java `we2zT  
*//文件访问(定位,写) "m +Eu|{  
package NetFox; /b,+YyWi%  
import java.io.*; N8(xz-6  
8r /]Q  
p,}-8#K[  
public class FileAccessI implements Serializable{ yrO'15TB  
FT73P0!8.  
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 i_ws*7B<  
RandomAccessFile oSavedFile; z<c^<hE:l  
long nPos; %Rv&VFg  
BDZB;DPb  
eKn&`\j6  
public FileAccessI() throws IOException %)*!(%\S*3  
{ W"4E0!r  
this("",0); +<6L>ZAL  
} )hj77~{ +  
2D`@$)KL  
{55{ YDqx  
public FileAccessI(String sName,long nPos) throws IOException )c5 M;/s  
{ 6XUcJ0  
oSavedFile = new RandomAccessFile(sName,"rw"); $s.:wc^  
this.nPos = nPos; _Hi;Y  
oSavedFile.seek(nPos); o%h"gbvMY!  
} N( E\  
;RZ@t6^  
W3* BdpTw  
public synchronized int write(byte[] b,int nStart,int nLen) @B5@3zYs  
{ [P8Y  
int n = -1; +Y(cs&V*  
try{ c#nFm&}dm  
oSavedFile.write(b,nStart,nLen); kCxmC<34  
n = nLen; 'p-jMD}O  
} dgpo4'c}  
catch(IOException e) s`xp6\$  
{ E-_)w  
e.printStackTrace (); '{XDhK  
} :k8>)x] )  
m8$6FN  
7CYu"+Ea  
return n; &0SGAJlec  
} UTKS<.q  
,e( |,u  
S6,AY(V  
} ;YNN)P%"  
\c>9f"jS_  
eS fT +UL  
/* C$ oY,A,  
**SiteInfoBean.java l_iucN  
*/ _1hc^j  
package NetFox; 9>u2; 'Ls  
&#v^y 3r  
A=!&2(  
public class SiteInfoBean { xB3;%Lc  
>8Zz<S&z  
dsX{  5  
private String sSiteURL; //Site's URL +mhYr]Z  
private String sFilePath; //Saved File's Path =$Sf]L  
private String sFileName; //Saved File's Name (f5!36mz  
private int nSplitter; //Count of Splited Downloading File J|_&3@r  
^M6v;8EU  
[ik D4p=  
public SiteInfoBean() /XS6X  
{//nSplitter的缺省值为5 '?t]iRCeI7  
//default value of nSplitter is 5 LW?] ~|  
this("","","",5); "5Oog<  
} 4ao oBY$  
]Rohf WHX  
o,9E~Q'`{  
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) u /JEQz1  
{ ESiNW&u2  
sSiteURL= sURL; |;'V":yDs  
sFilePath = sPath; ~6.AE/ow  
sFileName = sName; fF[n?:VV  
this.nSplitter = nSpiltter; |TF,Aj   
\D?6_ ,O  
hD{+V!{  
} B<DvH"+$  
l@Ma{*s6=5  
&WN4/=QW-J  
public String getSSiteURL() bB3Mpaw@  
{ /@R|*7K;9  
return sSiteURL; _o~<f)E[9  
} ].]yqD4P  
"6^tG[G%  
gg'lb{oG  
public void setSSiteURL(String value) 9X,dV7 yW  
{ Y oNg3  
sSiteURL = value; T nAd!  
} o4o&}  
\hQ[5>  
ncb?iJ/b^  
public String getSFilePath() \    
{ +N"A5U  
return sFilePath; 5Ft bZ1L  
} zCL/^^#  
[%YA42_`LD  
=+~e44!~D  
public void setSFilePath(String value) bM_Y(TgJ  
{ f% ZqK_CW  
sFilePath = value; [0yKd?e  
} hEsCOcEG  
YZ:YYcr  
r1EccY  
public String getSFileName() gR.zL>=_5e  
{ t9&)9,my  
return sFileName; \MsAdYR  
} .oH0yNFX  
u@}((V  
T=:O(R1*0  
public void setSFileName(String value) \:8~na+(  
{ @Rj&9/\L  
sFileName = value; =DvFY]9{  
} dl'pl  
e{:P!r aM  
d,iW#,  
public int getNSplitter() ( Z\OqG  
{ 5,I'6$J  
return nSplitter; 'Z+w\0}@  
} %lbSV}V)  
9bl&\Ykt.  
Ah='E$t  
public void setNSplitter(int nCount) +Qt=N6>  
{ />Tyiy]2uu  
nSplitter = nCount; i]Lt8DiRq  
} `/f9 mn  
} C 6Bh[:V&  
2uZ <q?=  
djS?$WBpU  
/* b(_PCVC  
**Utility.java (u@[}!  
*/ .6xP>!E}Q  
package NetFox; W tnZF]1:u  
.UakO,"z  
rhMsZ={M  
public class Utility { t]P[>{y  
ct3QtX0B  
Ym(^i h  
public Utility() m8rKH\FD}  
{ g[@Kd  
2JYp.CJv  
f*Xonb  
} i?z3!`m  
Kw3fpNd  
//线程睡眠 ^-w:D  
public static void sleep(int nSecond) .S`Ue,H  
{ "Fy34T0N  
try{ >J[g)$,  
Thread.sleep(nSecond); >"f,'S5*  
} BXO(B'1)]  
catch(Exception e) VE& ?Zd~  
{ 'C1=(PE%`  
e.printStackTrace (); ~&CaC  
} 3Ku!;uo!u  
} ] ^to r  
AT<gV/1l  
//日志 00Tm0rY  
public static void log(String sMsg) sD1L P  
{ SGZOfTcY  
System.err.println(sMsg); A,W-=TC  
} [V  T&  
{lT9gJ+  
im>Sxu@  
public static void log(int sMsg) ;tf1 #6{  
{ gd]vrW'wj  
System.err.println(sMsg); FviLlly6  
} -TU7GCb=  
} Nb>|9nu O  
%:h)8e-;  
-9~kp'_a  
/* L5(rP\B  
**TestMethod.java ' jZ2^  
*/ ;o,t *  
package NetFox; LZMdW #,[  
3%/]y=rA  
.6 !IO^`[  
public class TestMethod { &0K; Vr~D  
<&n3"  
}Y(Q7l  
public TestMethod() N6c']!aM@  
{ ///xx/weblogic60b2_win.exe Nv,[E+a2  
try{ $lOx 6rL  
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); Dw%>y93V  
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); mn{8"@Z  
SiteFileFetch fileFetch = new SiteFileFetch(bean); f~jx2?W  
fileFetch.start(); l$z[Vh^UU<  
} IPbdX@FeV  
catch(Exception e){e.printStackTrace ();} rFM`ne<zh  
Cnd*%CPZ  
Z@nM\/vLA  
} VCiJ]$`M  
zid?yuP  
#E2`KGCzW  
public static void main(String[] args) bS3qX{5  
{ KunK.m  
new TestMethod(); $|C%G6!s?@  
} yUq,9.6Ig  
} 5{zXh  
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