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http断点续传简单实现(java)

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/* |942#rM  
**SiteFileFetch.java F|oyrG  
*/ YV>&v.x0;  
package NetFox; _)YB*z5  
import java.io.*; \CS4aIp  
import java.net.*; jJ'NYG  
L`9.Gf  
+br' 2Pn  
public class SiteFileFetch extends Thread { 7;r3Bxa Q  
@$%.iQ7A;  
^'+#BPo9@  
SiteInfoBean siteInfoBean = null; //文件信息Bean %t74*cX  
long[] nStartPos; //开始位置 ^4Se=Hr z2  
long[] nEndPos; //结束位置 F/:%YR;  
FileSplitterFetch[] fileSplitterFetch; //子线程对象 Y$./!lVY  
long nFileLength; //文件长度 gnb+i`  
boolean bFirst = true; //是否第一次取文件 $j@P 8<M7  
boolean bStop = false; //停止标志 *;F<Q!i&v  
File tmpFile; //文件下载的临时信息 fI=p^k:  
DataOutputStream output; //输出到文件的输出流 G_ ~qk/7mF  
a6It1%a+  
//负责整个文件的抓取,控制内部线程(FileSplitterFetch类) ?hURNlR_Q  
public SiteFileFetch(SiteInfoBean bean) throws IOException Ruwp"T}mF  
{ m<*+^JN  
siteInfoBean = bean; %*gg6Q  
//tmpFile = File.createTempFile ("zhong","1111",new File(bean.getSFilePath())); Bw[#,_  
tmpFile = new File(bean.getSFilePath()+File.separator + bean.getSFileName()+".info"); "st+2#{  
if(tmpFile.exists ()) pDhUD}1G  
{ >-w# &T &K  
bFirst = false; iVmy|ewd  
read_nPos(); ^\yz`b(A0  
} T5:xia>8O  
else |X6R 2I  
{ 23Q 88z   
nStartPos = new long[bean.getNSplitter()]; 6J$I8b#/  
nEndPos = new long[bean.getNSplitter()]; \E05qk_;K  
} <w?k<%( 4  
cBZJ  
A2P.5EN  
p^ OHLT  
} yGX5\PSo  
>5 Y.  
'jy e*  
public void run() EV|W:;Sg  
{ (>lH=&%zj  
//获得文件长度 ;Uy}(  
//分割文件 FNo.#Z5+b  
//实例FileSplitterFetch ETdN<}m  
//启动FileSplitterFetch线程 5as5{"l  
//等待子线程返回 )6o%6$c  
try{ :C={Z}t/F  
if(bFirst) j|XL$Q  
{ }-9 c1&m  
nFileLength = getFileSize(); xjrL@LO#  
if(nFileLength == -1) s |o(~2j  
{ $Ny:At  
System.err.println("File Length is not known!"); nm %7e!{m  
} )gAqWbkB  
else if(nFileLength == -2)  &!wtH  
{ s={IKU&m[  
System.err.println("File is not access!"); wZKmU  
} eIhfhz?Q;#  
else jTW8mWNk]  
{ w`dSc@ :  
for(int i=0;i<nStartPos.length;i++) K@:t6  
{ 7m:TY>{  
nStartPos = (long)(i*(nFileLength/nStartPos.length)); i4M%{]G3Y  
} =&DuQvN,  
for(int i=0;i<nEndPos.length-1;i++) >Dz8+y  
{ Tiimb[|  
nEndPos = nStartPos[i+1]; Wo,93]  
} sNMF(TY  
nEndPos[nEndPos.length-1] = nFileLength; E #!.;AQ  
} w")m]LV  
} x]4>f[>*>  
/R>YDout}  
]a[2QQ+g  
//启动子线程 3bQq Nk  
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; JLg/fB3%  
for(int i=0;i<nStartPos.length;i++) jc,Q g2  
{ 1Cw$^jd  
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), .;(a;f+{;  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), kX)*:~*  
nStartPos,nEndPos,i); I<Mb /!TQ  
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); Il#ST  
fileSplitterFetch.start(); yDj'')LOQg  
} _'n]rQ'  
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), Rh)%;  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); T#vY(d  
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", $ P2*qpqy  
nEndPos = " + nFileLength); ^SM5oK  
// fileSplitterFetch[nPos.length-1].start(); D'^UZZlI^I  
{]dvzoE]  
|C0!mU  
//等待子线程结束 X}ihYM3y/  
//int count = 0; J5z\e@?.0\  
//是否结束while循环 B$S@xD $  
boolean breakWhile = false; Y)#,6\=U  
[ /<kPi  
Oh,Xjel  
while(!bStop) 9Sl5jn  
{ }j!C+i  
write_nPos(); CdtCxy5  
Utility.sleep(500); 5'<a,,RKu  
breakWhile = true; vN~joQ=d  
43~v1pf{!  
-M4VC^_  
for(int i=0;i<nStartPos.length;i++) /_yAd,^-+  
{ CBz=-Xr  
if(!fileSplitterFetch.bDownOver) w@\4ft6d  
{ +k0UVZZX?  
breakWhile = false; r"t,/@`n  
break; D z[ ,;  
} -"XHN=H  
} .B'ws/%5\  
if(breakWhile) BJ5^-|  
break; z f >(Y7M  
!P":z0K4  
Bw9O)++  
//count++; xU(b:D Z  
//if(count>4) o>&-B.zq  
// siteStop(); 5v sn'=yN  
} =Wz)(N  
def\=WyK  
m\_v{1g  
System.err.println("文件下载结束!"); ?=HoU3  
} Owv}lJ  
catch(Exception e){e.printStackTrace ();} 3{TE6&HIa  
} 8x8nQ *_  
AtqsrYj  
PO|gM8E1x?  
//获得文件长度 M<SVH_  
public long getFileSize() 1bjWWNzQA  
{ ):n'B` f}z  
int nFileLength = -1; eQMa9_  
try{ 6QNZ/Ox:  
URL url = new URL(siteInfoBean.getSSiteURL()); ,pUB[w\  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); HHOqJb{8S  
httpConnection.setRequestProperty("User-Agent","NetFox"); :!FGvR6  
s%A?B 8,  
=dp`4N  
int responseCode=httpConnection.getResponseCode(); V|/N-3M  
if(responseCode>=400) db>"2EE  
{ }|nEbM]#  
processErrorCode(responseCode); f?(g5o*2  
return -2; //-2 represent access is error vtc%MG1  
} iT+t  
H;+98AIy`  
bP%X^q~]A  
String sHeader; lXD=uRCI  
?/(*cA  
n;>r  
for(int i=1;;i++) ?`75ah  
{ biU ?>R  
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); []?*}o5&>T  
//Utility.log(in.readLine()); G)gb5VW k  
sHeader=httpConnection.getHeaderFieldKey(i); '}q/;}ih  
if(sHeader!=null) lQ4$d{m`  
{ 7Oi<_b  
if(sHeader.equals("Content-Length")) ]1I-e2Q-J  
{ {5+ 39=(  
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); .s|5AC[  
break; >xXq:4l>}  
} {yMkd4v  
} wp@6RJ  
else Zj0h0Vt  
break;  }s8xr>  
} 4z^~,7J^  
} g9IIC5  
catch(IOException e){e.printStackTrace ();} iL~(BnsF  
catch(Exception e){e.printStackTrace ();} BU|m{YZ$  
GbvbGEG  
d-gcXaA-8  
Utility.log(nFileLength); YI]/gWeu  
nd5.Py$  
!"ydl2  
return nFileLength; AR g]GV/L  
} y4H/CH$%  
8rNf4]5@X(  
}$ a *XY1  
//保存下载信息(文件指针位置) EWWCh0 {  
private void write_nPos() IcNZUZGE  
{ m`4N1egCt  
try{ vJ;0%;eu[!  
output = new DataOutputStream(new FileOutputStream(tmpFile)); BM87f:d  
output.writeInt(nStartPos.length); `'pfBVBz  
for(int i=0;i<nStartPos.length;i++) A^4#6],%v  
{ w!}kcn<  
// output.writeLong(nPos); C]3^:b+   
output.writeLong(fileSplitterFetch.nStartPos); uTy00`1  
output.writeLong(fileSplitterFetch.nEndPos); gGs"i]c  
} T6\d]  
output.close(); 4OG 1_6K  
} V! .I>  
catch(IOException e){e.printStackTrace ();} 8C I\NR{x8  
catch(Exception e){e.printStackTrace ();} -JclEp  
} p1IN%*IV+o  
,5x9o"N!  
9q2x}  
//读取保存的下载信息(文件指针位置) v}@Uc-(  
private void read_nPos() `*B6T7p1  
{ gj }Vnv1[  
try{ M0]J `fL@  
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); @2+'s;mUV  
int nCount = input.readInt(); WHRBYq_  
nStartPos = new long[nCount]; MQX9BJ%  
nEndPos = new long[nCount]; "~"=e  
for(int i=0;i<nStartPos.length;i++) /5?tXH"  
{ |#B)`r8  
nStartPos = input.readLong(); ) LohB,?  
nEndPos = input.readLong(); Y*S(uqM  
} ^>z+e"PQA  
input.close(); Y{8}z ZD  
} Uu|R]azbO  
catch(IOException e){e.printStackTrace ();} z%$M IC  
catch(Exception e){e.printStackTrace ();} c >xHaA:V  
} u>V~:q\X  
^KQZ;[B  
Kw`}hSE>o  
private void processErrorCode(int nErrorCode) cq$ _$jRx  
{ L; <Pod  
System.err.println("Error Code : " + nErrorCode); fhro"5/4  
} RuOse9  
U bh)}G,Mg  
\CYKj_c  
//停止文件下载 xBE}/F$ 45  
public void siteStop() 5zF$Q{3  
{ '.7ER  
bStop = true; ,fhK  
for(int i=0;i<nStartPos.length;i++) 3WPZZN<K9  
fileSplitterFetch.splitterStop(); 7<LCX{Uw  
4^ZbT  
@\U] hN?  
} I@(3~ Ab  
} 12}!oS~_  
//负责部分文件的抓取 n_6#Df*  
**FileSplitterFetch.java _I0=a@3  
*/ ye4GHAm,p  
package NetFox; 3O|2Z~>3  
0*KL*Gn  
yxi*4R  
import java.io.*; ,S&p\(r.  
import java.net.*; D*g K,`  
m=60a@o]  
$,nidK!"  
public class FileSplitterFetch extends Thread { <_SdW 5BF<  
?:+p#&I  
e[db?f2!  
String sURL; //File URL  4Gj  
long nStartPos; //File Snippet Start Position 2F/oWt|w?  
long nEndPos; //File Snippet End Position ((6?b5[  
int nThreadID; //Thread's ID j/1 f|x  
boolean bDownOver = false; //Downing is over $|I hO  
boolean bStop = false; //Stop identical <Kk?BRxi  
FileAccessI fileAccessI = null; //File Access interface |J~A )Bw?  
KB gFS%-W  
u&e?3qKX(  
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException H?;@r1ZAn  
{ i4)]lWnd  
this.sURL = sURL; {`9J8qRY  
this.nStartPos = nStart; 5m?9O7Pg  
this.nEndPos = nEnd; [f]:h Ji  
nThreadID = id; }synU]^7\  
fileAccessI = new FileAccessI(sName,nStartPos);//定位 ,hCbx #h  
} hSaw)g`w  
C-H6l6,  
k>:\4uI|<\  
public void run() QiNLE'19^  
{ 8TYoa:pZ  
while(nStartPos < nEndPos && !bStop) w]US-7  
{ Q}1qt4xy*  
{&nDm$KTD  
H5be5  
try{ +ux`}L(  
URL url = new URL(sURL); Li\b ,_C  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection ();  y)3OQ24  
httpConnection.setRequestProperty("User-Agent","NetFox"); Lv *USN  
String sProperty = "bytes="+nStartPos+"-"; fBKN?]BdN  
httpConnection.setRequestProperty("RANGE",sProperty); fbkAu  
Utility.log(sProperty); 22`e7  
/`7G7pQ+  
Q fL8@W~e  
InputStream input = httpConnection.getInputStream(); g>{t>B%v^K  
//logResponseHead(httpConnection); 9 }  ]C  
o}yA{<"  
U:8cz=#  
byte[] b = new byte[1024]; 7/dp_I}cO  
int nRead; 3(1UI u  
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) 7Kt i&T  
{  ;ih;8  
nStartPos += fileAccessI.write(b,0,nRead); y 48zsm{  
//if(nThreadID == 1) Jjh=zxR>  
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); bs)Ro/7}  
} 3vEwui-5  
M+7jJ?n  
1(jx.W3  
Utility.log("Thread " + nThreadID + " is over!"); 'i 8`LPQ  
bDownOver = true; t!0 IQ9\[*  
//nPos = fileAccessI.write (b,0,nRead); tNxKpA |F  
} cK'}+  
catch(Exception e){e.printStackTrace ();} MgH O WoF  
} LqS_%6^  
} K\5/||gi  
~_ko$(;A  
}jYVB|2  
//打印回应的头信息 kM3#[#6$!  
public void logResponseHead(HttpURLConnection con) .<6'*X R  
{ :PB W=W  
for(int i=1;;i++) ![m6$G{y  
{ A9LVS&52  
String header=con.getHeaderFieldKey(i); ^h"@OEga?  
if(header!=null) 'NDr$Qc3  
//responseHeaders.put(header,httpConnection.getHeaderField(header)); JC7:0A^  
Utility.log(header+" : "+con.getHeaderField(header)); P@U2Q%\  
else ;6*$!^*w  
break; _hEr,IX=J  
} ^-(DokdBn  
} i_p-|I:hQ  
,j eC7-tX  
 Bm&6  
public void splitterStop() 1/c+ug!y  
{ =lx~tSiS  
bStop = true; TmJXkR.5  
} %t]{C06w+{  
SxL/]jWR7  
kk}_AZ0eK  
} |q Pu*vR  
z]!w@:  
[$Jsel<T=  
/* t_\&LMD  
**FileAccess.java 1?,C d  
*//文件访问(定位,写) vHb^@z=  
package NetFox; h/*@ML+bB8  
import java.io.*; "lL/OmG  
5JS*6|IbD{  
Ij:yTu   
public class FileAccessI implements Serializable{ Twk<<  
*C.Kdf3w  
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 &5hs W1`  
RandomAccessFile oSavedFile; gq~"Z[T  
long nPos; f0*_& rP  
ow#8oUf=  
,Uy;jk  
public FileAccessI() throws IOException i\=I` Yn+  
{ wqgKs=y  
this("",0); Nop61zj  
} $}=r 45e0K  
xp*d:  
)*aAkM  
public FileAccessI(String sName,long nPos) throws IOException =Ea,8bpn  
{ '30JJ0  
oSavedFile = new RandomAccessFile(sName,"rw"); ulfs Z:  
this.nPos = nPos; w4l]rH  
oSavedFile.seek(nPos); tMyMA}`  
} 7t+H94KG7  
N:,V{Pw  
=FfR?6 ~  
public synchronized int write(byte[] b,int nStart,int nLen) l|M|;5TW  
{ E CPSE {  
int n = -1; "e/"$z'ca  
try{ !(y(6u#  
oSavedFile.write(b,nStart,nLen); !p_l(@f  
n = nLen; \!*F:v0g^  
} ,q$2D,dz  
catch(IOException e) ~w(A3I.  
{ ^=qV)j  
e.printStackTrace (); S`vw<u4t  
} z2q!_ ~  
,I:[-|Q  
S(lqj6aa}  
return n; WN o+%  
} *Zn,v-d  
qipS`:TER  
%cASk>^i  
} 2~h Q   
-o57"r^x  
`0-i>>  
/*  nWUau:%  
**SiteInfoBean.java jn oX%3d-  
*/ 4thPR}DH}  
package NetFox; %m$t'?  
!ED,'d%J  
@Y#TWt#  
public class SiteInfoBean { )2r_EO@3HP  
ZL9|/ PY  
eGo$F2C6E  
private String sSiteURL; //Site's URL },#AlShZu  
private String sFilePath; //Saved File's Path 2t7=GA+j  
private String sFileName; //Saved File's Name >Fc=F#tA9  
private int nSplitter; //Count of Splited Downloading File 5,R<9FjW  
1h`#H:  
!X=93%  
public SiteInfoBean() oOGFg3X  
{//nSplitter的缺省值为5 '(8} <(%  
//default value of nSplitter is 5 d%oHcn  
this("","","",5); {3 >`k.w  
} ,fj~BkW{  
T? ,Q=.  
#vTF:r  
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) 6>h"Lsww  
{ |2I p*  
sSiteURL= sURL; 4hUUQ;xj  
sFilePath = sPath; bLUyZ3m!  
sFileName = sName; _;-b ZH  
this.nSplitter = nSpiltter; -U@ycx|r  
axv-U dE;  
"rw'mogRL  
} 7Q aZ|\c  
A$TF a:O|  
Q|Nw @7$`  
public String getSSiteURL() p(A[ah_  
{ E,[v%Xw   
return sSiteURL; s$/ Z+"f(  
} 4 rD&Lg'  
Y7`Dx'x  
$EZr@n  
public void setSSiteURL(String value) RG- ,<G`  
{ x^ sTGd  
sSiteURL = value; t0)hd X  
} EtDzmpJR>  
`>`{DEDx{5  
7[8d-Sf24{  
public String getSFilePath() Vje LPbk)  
{ &l W~ot1,  
return sFilePath; 7Y^2JlZu=  
} 'zuA3$SR  
$oZV 54  
mMad1qCi7  
public void setSFilePath(String value) 5 Praj  
{ 3 FLht L  
sFilePath = value; g+=f=5I3  
} a<Ps6'  
$HV`bJ5!L*  
a6g+"EcH#'  
public String getSFileName() hle@= e/n  
{ }k6gO0z  
return sFileName; <:~'s]`zf  
} M_\)<a(8  
bd`}2vr  
=z2g}X  
public void setSFileName(String value) >8DZj&j  
{ -)E6{  
sFileName = value; mQ:5(]v  
} P L*kjrLu7  
|A:+[35  
o&rNM5:  
public int getNSplitter() :4S~}}N  
{ MT.D#jv&  
return nSplitter; 5i&+.?(Z=  
} (%|L23  
q]z%<`.9*  
uJ%XF*>_D  
public void setNSplitter(int nCount) | PzXN+DW  
{ zvh&o*\2<d  
nSplitter = nCount; *7!*kq g!u  
} l1}HJmom  
} i>AKXJ+  
08;t%[R  
~@EBW3>~5  
/* \ dZD2e4  
**Utility.java F$H^W@<w  
*/ SR&'38UCe  
package NetFox; ^+Stvj:N  
mX QVL.P\  
.k:Uj-&  
public class Utility { |[ ,|S{  
MNsgD3  
tU(vt0~b  
public Utility() uHpSE?y/  
{ )x&OdFX  
e=EM07z  
_;`g*Kx  
} )l*6zn`z  
uOnyU+fZV  
//线程睡眠 >&2n\HR\  
public static void sleep(int nSecond) +G<9|-  
{ ,daZ KxT  
try{ <{b#nPc!,#  
Thread.sleep(nSecond); +UC-  
} X |X~|&j  
catch(Exception e) ?*)wQZt;  
{ ' CO3b,  
e.printStackTrace (); Na2n4x!  
} G/5]0]SO  
} ^J$?[@qD  
/J0ctJ2k  
//日志 Cz1o@ rt  
public static void log(String sMsg) 60&4?<lR4  
{ - d(RK_  
System.err.println(sMsg);  [EU \-  
} $mp'/]  
_f5n t:-  
J`4{O:{4  
public static void log(int sMsg) U:o(%dk  
{ $S _VR  
System.err.println(sMsg); fA>FU/r  
} wX*F'r"z  
} W6[# q%o  
dF/HKBJ  
^-i<TJ  
/* `;fk,\8t%  
**TestMethod.java X0QLT:J b  
*/ -^%YrWgd?  
package NetFox; XKq}^M&gy  
N N;'QiE  
J|A:C[7 2  
public class TestMethod { RY]Vo8  
^sA"&Vdr^  
F ak"u'~  
public TestMethod() M;Dk$B{;R  
{ ///xx/weblogic60b2_win.exe 6$|!_94>*)  
try{ ~9KxvQzt  
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); j\S}TaH0e  
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); -h/KrB  
SiteFileFetch fileFetch = new SiteFileFetch(bean); {a `#O9  
fileFetch.start(); P,@ :?6  
} 8P#jC$<  
catch(Exception e){e.printStackTrace ();} xfyUT^  
4dwG6-  
_;1H2o2f  
} ;.<0lnV  
8={ " j  
}.j09[<  
public static void main(String[] args) iHB1/  
{ g,N"o72)  
new TestMethod(); sC=fXCGW\p  
} *j0kb"#  
} jg_##Oha  
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