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http断点续传简单实现(java)

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/* V;>p@uE,P  
**SiteFileFetch.java {~Phc 2z  
*/ %R}}1  
package NetFox; Rrsz{a  
import java.io.*; UA{A G;  
import java.net.*; &Uzg&eB  
A H`6)v<f  
uYV# '%  
public class SiteFileFetch extends Thread { zV%U4P)Dao  
_m;Y'  
 M7hff4c  
SiteInfoBean siteInfoBean = null; //文件信息Bean 63ht|$G  
long[] nStartPos; //开始位置 RsY|V|<  
long[] nEndPos; //结束位置 `?~pk)<C].  
FileSplitterFetch[] fileSplitterFetch; //子线程对象 9HWtdJ+^C=  
long nFileLength; //文件长度 'DVPx%p  
boolean bFirst = true; //是否第一次取文件 ~~>D=~B0'  
boolean bStop = false; //停止标志 !)ee{CwNc  
File tmpFile; //文件下载的临时信息 d6wsT\S  
DataOutputStream output; //输出到文件的输出流 $LKniK  
i/~A7\:8%  
//负责整个文件的抓取,控制内部线程(FileSplitterFetch类) x#'# ~EO-G  
public SiteFileFetch(SiteInfoBean bean) throws IOException uQrD}%GI  
{ P.LMu  
siteInfoBean = bean; nd-y`@z  
//tmpFile = File.createTempFile ("zhong","1111",new File(bean.getSFilePath())); %|4Nmf$:Og  
tmpFile = new File(bean.getSFilePath()+File.separator + bean.getSFileName()+".info"); `NrxoU=  
if(tmpFile.exists ()) ]Rz]"JZ\S  
{ "`16-g97  
bFirst = false; ]>&au8  
read_nPos(); )~rN{W<s`H  
} GBN^ *I  
else ~fEgrF d  
{ 2}t2k>  
nStartPos = new long[bean.getNSplitter()]; TN(1oJ:  
nEndPos = new long[bean.getNSplitter()]; 7)z^*;x  
} m\[r6t]V  
98G>I(Cw%  
tZwZZ0]Z  
CsXIq.9  
} )V} t(>V  
sAWUtJ  
UZv^3_,qz  
public void run() IrJCZsk  
{ e5C560  
//获得文件长度 }>>BKn   
//分割文件 v-EcJj%  
//实例FileSplitterFetch 1%t9ic  
//启动FileSplitterFetch线程 Y@F@k(lOo  
//等待子线程返回 mZ'`XAS~;  
try{ c V=h 8F  
if(bFirst) (m25ZhW  
{ Z_Hc":4i  
nFileLength = getFileSize(); YrFB~z.V  
if(nFileLength == -1) *e!0ZB3J  
{ ^ola5wD  
System.err.println("File Length is not known!"); k#&d`?X  
} )mS Aog<  
else if(nFileLength == -2) gm\P`~+o  
{ V~%!-7?  
System.err.println("File is not access!"); c&J,O1){\  
} 44b;]htv  
else {IJ,y27  
{ rOEk%kJ  
for(int i=0;i<nStartPos.length;i++) .sgP3Ah  
{ .e~17}Ka}  
nStartPos = (long)(i*(nFileLength/nStartPos.length)); =Z2Cg{z  
} a)/!ifJ;  
for(int i=0;i<nEndPos.length-1;i++) 'WUd7  
{ jIaAx_  
nEndPos = nStartPos[i+1]; fKb8)PDP  
} |1uyJ?%B  
nEndPos[nEndPos.length-1] = nFileLength; [}}?a   
} F$F,I,$ "  
} ' cR||VX  
tI~.3+F  
<!Ed ND=  
//启动子线程 mfc\w'  
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; IC"bg<L,*  
for(int i=0;i<nStartPos.length;i++) &A)AV<=>T  
{ 8GgZAu'X  
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), a6cq0g[#z  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), tN&4t xB  
nStartPos,nEndPos,i); ;shhg z$  
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); DD{-xCCR  
fileSplitterFetch.start(); * G!C 'w\$  
} =dSH8C"  
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), CB]#`|f  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); rozp  
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", @8{-B;   
nEndPos = " + nFileLength); -fKo~\Pr  
// fileSplitterFetch[nPos.length-1].start(); agp`<1h9  
LX2rg\a+%  
sxkWg>  
//等待子线程结束 _FR_6*C)5  
//int count = 0; p8,Rr{  
//是否结束while循环 %/iD@2r  
boolean breakWhile = false; uj;tmK>;  
yq]=+X>(  
jkTC/9AE|  
while(!bStop) v"ZNS  
{ nI]8w6eCV  
write_nPos(); 0vR gmn  
Utility.sleep(500); e!k1GTH^  
breakWhile = true; Uq/FH@E=  
wX<w)@  
[QwEidX|  
for(int i=0;i<nStartPos.length;i++) )B'&XLK  
{ i7D[5!  
if(!fileSplitterFetch.bDownOver) wr>[Eo@%\  
{ ?i'N 9 /(  
breakWhile = false; F#NuZ'U  
break; t$~CLq5ad  
} v_^>*Vm*  
} U1nObA  
if(breakWhile) &GYnGrw?@  
break; %x{jmZ$}  
o_ng{SL  
F/p/&9  
//count++; -@bOFClE  
//if(count>4) 6.5E d-  
// siteStop(); s R/z)U_  
} V9`?s0nn^  
Pa)'xfQ$Y6  
M18 >%zM  
System.err.println("文件下载结束!"); 5?l8;xe`{f  
} x Zp`  
catch(Exception e){e.printStackTrace ();} tBU n KPT  
} %vn"tp  
|Yb]@9 >vn  
zu/BDyF  
//获得文件长度 ^Mvgm3hg  
public long getFileSize() Ln+;HorZ]  
{ cvOCBg38BH  
int nFileLength = -1; (E(J}r~E  
try{ T8^`<gr.  
URL url = new URL(siteInfoBean.getSSiteURL()); Ob!NC&  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 2nra@  
httpConnection.setRequestProperty("User-Agent","NetFox"); VN3 [B eH  
Z-%zR'-?*  
65]>6D43  
int responseCode=httpConnection.getResponseCode(); xQUskjv/  
if(responseCode>=400) s#cb wDT  
{ C*X=nezq  
processErrorCode(responseCode); Q&5s,)w-  
return -2; //-2 represent access is error !#y_vz9  
} G]v BI=  
iH a:6  
?i{/iH~Sf  
String sHeader; p C^=?!:U  
R1 C}S  
$ U=j<^R}a  
for(int i=1;;i++) :%[mc-6.  
{ /6 y9 u}  
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); F:7 d}Jx  
//Utility.log(in.readLine()); 43.Q);4  
sHeader=httpConnection.getHeaderFieldKey(i); ^V}c8 P|  
if(sHeader!=null) ]A=yj@o$xN  
{ Y;)l  
if(sHeader.equals("Content-Length")) P+L#p(K  
{ ;~,)6UX7  
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); N?EeT}m_  
break; utu V'5GD  
} FW"n+7T  
} Nn#;Kjul.  
else G)IK5zCDd  
break; V1#:[o63+  
} N&yr?b'!-*  
} $;pHv<  
catch(IOException e){e.printStackTrace ();} z[Ah9tM%  
catch(Exception e){e.printStackTrace ();} 8-B6D~i  
=f?vpKq40  
*qZBq&7tb  
Utility.log(nFileLength); i&TWIl8  
cY^'Cj  
#=V\WQb  
return nFileLength; :u]QEZ@@  
} ;#bDz}|\AN  
:\Q#W4~p  
e_YTh^wU  
//保存下载信息(文件指针位置) 6bDizS}  
private void write_nPos() dOT7;@   
{ i@`qam   
try{ %(1Jt "9|  
output = new DataOutputStream(new FileOutputStream(tmpFile)); |b4f3n  
output.writeInt(nStartPos.length); Skg}/Ek  
for(int i=0;i<nStartPos.length;i++) +!Q*ie+q  
{ S3UJ)@ E  
// output.writeLong(nPos); u!-v1O^[  
output.writeLong(fileSplitterFetch.nStartPos); &gF9VY  
output.writeLong(fileSplitterFetch.nEndPos); [*J?TNk  
} :85QwN]\  
output.close(); WF_ v>g:g  
} gNJdP!(t  
catch(IOException e){e.printStackTrace ();} !bIE%cq  
catch(Exception e){e.printStackTrace ();} EQtYb"_  
} 5?Ukf$)x  
oj/#wF+  
K&VMhMVb  
//读取保存的下载信息(文件指针位置) r=HL!XFk  
private void read_nPos() bU\T  
{ :K~sazs7J  
try{ G0A\"2U  
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); ,8.$!Zia  
int nCount = input.readInt(); >,ABE2t5  
nStartPos = new long[nCount]; e3mFO+  
nEndPos = new long[nCount]; i}e/!IVR3  
for(int i=0;i<nStartPos.length;i++) LGK&&srJs  
{ F/PH=Dk  
nStartPos = input.readLong(); T/FZn{I  
nEndPos = input.readLong(); u9m ~1\R*  
} iR"6VO  
input.close(); |xF!3GGms  
} v\@pZw=x  
catch(IOException e){e.printStackTrace ();} 6zi 5#23  
catch(Exception e){e.printStackTrace ();} (tyky&$!  
} $ V !25jQ  
)5NWUuH 5  
^(s(4|  
private void processErrorCode(int nErrorCode) erKi*GssZ  
{ O!t=,F1j  
System.err.println("Error Code : " + nErrorCode); S5kD|kJ  
} R^mkQb>m.  
"G^TA:O:=  
c^rWS&)P  
//停止文件下载 6RG63+G  
public void siteStop() u* G+=aV.6  
{ g^}C/~b[  
bStop = true; yDJy'Z_F{  
for(int i=0;i<nStartPos.length;i++) Gr>CdB>~+  
fileSplitterFetch.splitterStop(); ol K+|nR  
n.i 8?:  
.SLpgYFL{  
} mo+!79&  
} l3*GQ~m7  
//负责部分文件的抓取 l<p<\,nV$  
**FileSplitterFetch.java $Dd-2p   
*/ -&Q+x,.%  
package NetFox; ?6]B6  
!"o\H(siT  
K$:+]fJK  
import java.io.*; }g@ '^v  
import java.net.*; O c.fvP^ZD  
O._\l?m  
Qea"49R  
public class FileSplitterFetch extends Thread { eY-h<K)y  
@lq)L  
A;^ iy]"  
String sURL; //File URL ]28j$)6  
long nStartPos; //File Snippet Start Position oaZdvu@y  
long nEndPos; //File Snippet End Position C_'EO<w$  
int nThreadID; //Thread's ID VR .t  
boolean bDownOver = false; //Downing is over D.-G!0!  
boolean bStop = false; //Stop identical >28l9U  
FileAccessI fileAccessI = null; //File Access interface 9 *uK]/c  
*?*~<R  
vaJl}^T  
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException ^BM !TQ%!  
{ 8;L;R ~Q  
this.sURL = sURL; PxQQfI>  
this.nStartPos = nStart; &CcW(-  
this.nEndPos = nEnd; 0b/@QgJ  
nThreadID = id; {bADMj1  
fileAccessI = new FileAccessI(sName,nStartPos);//定位 }n "5r(*^@  
} SQhVdYU1'  
Faa>bc~E  
{6WG  
public void run() Zk/ejhy0  
{ `N&*+!O%  
while(nStartPos < nEndPos && !bStop) $2,tT;50g  
{ e&2,cQRFV  
Te[v+jgLY,  
W/%hS)75  
try{  '6})L  
URL url = new URL(sURL); 7{(UiQbf  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); ]jY^*o[  
httpConnection.setRequestProperty("User-Agent","NetFox"); -8Hc M\b  
String sProperty = "bytes="+nStartPos+"-"; |d&C<O;f  
httpConnection.setRequestProperty("RANGE",sProperty);  ,vO\n^  
Utility.log(sProperty); S0Io$\ha  
wP*3Hx;S  
o&&`_"18  
InputStream input = httpConnection.getInputStream(); ^EKRbPA9:<  
//logResponseHead(httpConnection); BWvM~no  
iC5HrOl6U  
%)r:!R~R  
byte[] b = new byte[1024]; y/ Bo 4fM  
int nRead; <ch}]-_  
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) 2m]4  
{ ErJ/h?+  
nStartPos += fileAccessI.write(b,0,nRead); c|JQ0] K  
//if(nThreadID == 1) IG# wY  
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); s9a`2Wm  
} }^0'IAXi  
FwlD P  
!mTq6H12 !  
Utility.log("Thread " + nThreadID + " is over!"); vBOY[>=  
bDownOver = true; !'~Ldl  
//nPos = fileAccessI.write (b,0,nRead); 6r`N\ :18  
} FZn1$_Svr  
catch(Exception e){e.printStackTrace ();} tW4X+d"  
} ju'a Uzn  
} ]hS<"=oj  
>zDQt7+g;  
CuH4~6  
//打印回应的头信息 -3i(N.)<;  
public void logResponseHead(HttpURLConnection con) AWi>(wk<  
{ c+E\e]{  
for(int i=1;;i++) !L8q]]'XM  
{ Sir1>YEm  
String header=con.getHeaderFieldKey(i); qR!ZtJ5j  
if(header!=null) k}F7Jw#.  
//responseHeaders.put(header,httpConnection.getHeaderField(header)); ;Z"MO@9:  
Utility.log(header+" : "+con.getHeaderField(header)); f|M^UHt8*  
else K}cA%Y  
break; R;pW,]}g,  
} [ i, [^  
} E"_{S.Wc  
1HKA`]D"p  
0?8>{!I  
public void splitterStop() _hyqHvP  
{ -&`_bf%M  
bStop = true; E b:iym0  
} \Xmp lG:  
k kAg17 ^  
y>x"/jzF#  
} iAQ[;M 3p  
y705  
2w3LK2`ZL  
/* i KQj[%O  
**FileAccess.java u-|%K.A  
*//文件访问(定位,写) -%Vh-;Ie(  
package NetFox; d@g29rs  
import java.io.*; +B " aUF  
L=qhb;  
|Vqm1.1/Zv  
public class FileAccessI implements Serializable{ &hkD"GGe  
K"XwSZ/  
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 T@.+bD  
RandomAccessFile oSavedFile; &Pm@+ML*x  
long nPos; P$Vh{]4i{  
fsPNxy"_  
6]%=q)oL[  
public FileAccessI() throws IOException P8ej9ULX,  
{ @}H'2V  
this("",0); MYvz%7  
} t2{(ETV  
] 9C)F*r7  
zA6C{L G3  
public FileAccessI(String sName,long nPos) throws IOException Qc-W2%  
{ l<uI-RX "  
oSavedFile = new RandomAccessFile(sName,"rw"); Uz,P^\8^$  
this.nPos = nPos; Jj [3rt?8  
oSavedFile.seek(nPos); Mn/  
} gizY4~ j  
1}|y^oB\-  
yN{**?b  
public synchronized int write(byte[] b,int nStart,int nLen) M !"Q7>d  
{ mfI[9G  
int n = -1; Bf00&PE;  
try{  2=;ZJ  
oSavedFile.write(b,nStart,nLen); hfLe<,  
n = nLen; sj&(O@~R  
} r+[g.`  
catch(IOException e) K/C}  
{ iUh7eR9  
e.printStackTrace (); D9NRM;v  
}  +qj Z;5(  
*!"T^4DEg  
> `eo0  
return n; faLfdUimJ  
} Q+K]:c  
uc!6?+0h  
,B/TqPP  
} ~h8k4eM  
,Aq, f$5V  
c/bT5TIEWs  
/* C$])q`9  
**SiteInfoBean.java (AZneK :*  
*/ ld(_+<e  
package NetFox; / zNVJhC  
:/=P6b;  
dfVI*5[Z  
public class SiteInfoBean { ( zm!_~1  
V4"o.G3\o  
st"@kHQ3  
private String sSiteURL; //Site's URL OI)k0t^;D  
private String sFilePath; //Saved File's Path 0K^@P #{hd  
private String sFileName; //Saved File's Name D&mPYxXL  
private int nSplitter; //Count of Splited Downloading File Fczia0@z  
%1;Y`>  
wd|^m%  
public SiteInfoBean() 5?>Q[a.Ne  
{//nSplitter的缺省值为5 "N%W5[C{  
//default value of nSplitter is 5 j^ 8Hjg  
this("","","",5); 7SkW!5  
} mXJG &EA  
x?{l<mc  
7]L}~  
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) u];\v%b  
{ P!9-!+F"  
sSiteURL= sURL; V e[Kv07  
sFilePath = sPath; :X9;KoJl-V  
sFileName = sName; U/U_q-z]  
this.nSplitter = nSpiltter; 0[ n;ZL~  
/8_x]Es/  
p |;#frj  
} E?K(MT&@  
t x1TtWo  
_pS)bx w  
public String getSSiteURL() d<\X)-"  
{ +BI%. A`2  
return sSiteURL;  5 YIk  
} <Vyl*a{%  
 /*S6/#  
p0Ij 4   
public void setSSiteURL(String value) '#lEUlB  
{ 3WkrG.$[b  
sSiteURL = value; q}JP;p(#  
} 9~f RYA*  
}236{)DuN  
Pa\yp?({q  
public String getSFilePath() K)`l > o1  
{ xWQQX  
return sFilePath; M _Lj5`  
} uZ1G,9  
"[L+LPET  
=%FhY^-  
public void setSFilePath(String value) _3KfY  
{ LwQYO'X  
sFilePath = value; `$;%%/tx  
} MGKSaP;x  
g( eA?  
S^e e<%-  
public String getSFileName() #{bT=:3a  
{ +>mU4Fwp  
return sFileName; Z79Y$d>G<E  
} %. IW H9P7  
7&|&y SCu  
d5LL( "  
public void setSFileName(String value) [DSzhi]  
{ J72kjj&C  
sFileName = value; .ddf'$6h  
} z{> )'A/  
<e8Ux#x/  
=p!Hl#  
public int getNSplitter() $kQQdF  
{ 8`w#)6(V  
return nSplitter; l=&Va+K  
} 1NlpOVq:)  
^''3}<Ep  
60 p*4>^v  
public void setNSplitter(int nCount) zZCssn;[  
{ l(tMo7iPa  
nSplitter = nCount; DoJ3zYEk  
} XlxB%  
} s)~H_,  
P<xCg  
Wf$P+i*  
/* ,n{ |d33  
**Utility.java _3Q8R}  
*/ A}03s6^i;  
package NetFox; `~W?a  
&>auW}r  
O`0A#h&No  
public class Utility { DVyxe}  
)d?L*X~y'  
5fhe{d"si  
public Utility() T 3 +lYE  
{ pXxpEv  
9d,2d5Y  
pB]+c%\  
} Je~Ybh  
]M9r<x*  
//线程睡眠 ZEU/6.  
public static void sleep(int nSecond) =g^JJpS  
{ {B6tGLt#bf  
try{ `OyYo^+D|.  
Thread.sleep(nSecond); Rwz (20n\^  
} Q(YQ$ i"S  
catch(Exception e) }W R?n  
{ ;=ERm=  
e.printStackTrace (); 3H/4$XJB  
} <Okl.Iz>  
} ji|tc9#6  
mOi 8W,2  
//日志 -jsk-,  
public static void log(String sMsg) lMBXD?,,J  
{ wS1zd?  
System.err.println(sMsg); !"x&tF  
} ?qjlWCV|e  
A4|a{\|$  
|b:91l  
public static void log(int sMsg) .EoLJHL }  
{ V2|XcR  
System.err.println(sMsg); % g*AGu`  
} ZiOL7#QWX  
} onAC;<w  
1 9C=' TMS  
VpkkiN  
/* -gKo@I  
**TestMethod.java +gOv5Eno-  
*/ [8Zvs=1  
package NetFox; f"G?#dW/1  
aC2\C=ru_  
N-Nq*  
public class TestMethod { GE[J`?E]  
f'<MDLl  
VBK9te,A  
public TestMethod() nZ2mY!*  
{ ///xx/weblogic60b2_win.exe kMLWF  
try{ \.<V~d?  
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); =9JKg4I6  
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); r/vRaOg>X  
SiteFileFetch fileFetch = new SiteFileFetch(bean); r8E)GBH-|  
fileFetch.start(); /Z*XKIU6v/  
} g4 |s9RMD  
catch(Exception e){e.printStackTrace ();} 7 a}qnk %  
DVq 5[ntG  
dLMKfh/4Q  
} 2,X~a;+  
eD481r  
L(2KC>GvA  
public static void main(String[] args) %kJ_o*"  
{ pkL&j<{  
new TestMethod(); Yw\PmRL"p  
} fc #zhp5bX  
} ,1+)qv#|i  
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