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http断点续传简单实现(java)

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/* J+qcA}  
**SiteFileFetch.java fLuOxYQbf  
*/ )24 1-b V  
package NetFox; + $Lc'G+:  
import java.io.*; Rab7Y,AA  
import java.net.*; MVp+2@)}s  
t28 y=nv  
odTIz{9qG  
public class SiteFileFetch extends Thread { stq%Eg?  
:MF+`RpL  
9i!|wkx  
SiteInfoBean siteInfoBean = null; //文件信息Bean W'5c%SI  
long[] nStartPos; //开始位置 zCj#Nfm  
long[] nEndPos; //结束位置 5&}p'6*K  
FileSplitterFetch[] fileSplitterFetch; //子线程对象 s<8|_Dt  
long nFileLength; //文件长度 X7)B)r}AG  
boolean bFirst = true; //是否第一次取文件 VW**N}1#C  
boolean bStop = false; //停止标志 xsx0ZovhY  
File tmpFile; //文件下载的临时信息 *,Sa*-7(  
DataOutputStream output; //输出到文件的输出流 `m-7L  
E~`<n]{G-C  
//负责整个文件的抓取,控制内部线程(FileSplitterFetch类) ?b?YiK&yz  
public SiteFileFetch(SiteInfoBean bean) throws IOException AN+S6t  
{ o_.`&Q6n  
siteInfoBean = bean; Gp1?drF6  
//tmpFile = File.createTempFile ("zhong","1111",new File(bean.getSFilePath())); eMUt%zvb  
tmpFile = new File(bean.getSFilePath()+File.separator + bean.getSFileName()+".info"); x#'v}(v  
if(tmpFile.exists ()) G@,XUP  
{ Q'Y7PG9m~  
bFirst = false; Ym9~/'%]  
read_nPos(); _[y<u})  
} (6i. >%|_  
else =la~D]T*g  
{ @5cY5e*i{  
nStartPos = new long[bean.getNSplitter()]; fh9w5hT={  
nEndPos = new long[bean.getNSplitter()]; ;sY n=r  
} 4R9y~~+  
+<sv/gEt  
cTdX'5  
q)y<\cEO  
} e^-CxHwA-  
xDn#=%~+x  
uiaZ@  
public void run() gLWbd~  
{ pUeok+k_  
//获得文件长度 gO_d!x*  
//分割文件 )8V=!73  
//实例FileSplitterFetch G4J)o?:m@  
//启动FileSplitterFetch线程 uVzvUz{b  
//等待子线程返回 mfr7w+DK  
try{ ,xy$h }g  
if(bFirst) .\"8H1I\T  
{ ?PU7xO;_  
nFileLength = getFileSize(); .-cx9&  
if(nFileLength == -1) e0`5PVJ  
{ &>vfm9  
System.err.println("File Length is not known!"); Z \;{e'#o  
} \T^ptj(0  
else if(nFileLength == -2) Z<[:v2  
{ f SMy?8  
System.err.println("File is not access!"); T!t9`I0Zz  
} dEPLkv  
else tIo b  
{ ^8 cq qu  
for(int i=0;i<nStartPos.length;i++) ulNMqz\.  
{ kB_T9$0e#  
nStartPos = (long)(i*(nFileLength/nStartPos.length)); =$\9t$A  
} |6b&khAM  
for(int i=0;i<nEndPos.length-1;i++) Ko %e#q-  
{ Ypx"<CKP}  
nEndPos = nStartPos[i+1]; 4.q^r]m*  
} *+j r? |  
nEndPos[nEndPos.length-1] = nFileLength; noO#o+ Jg#  
} )^j62uv  
} >ui;B$=  
hWRr#030  
Tvd: P^ C  
//启动子线程 G/yYIs  
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; Z8\/Fb  
for(int i=0;i<nStartPos.length;i++) G)&S%R!i\N  
{ uevhW  
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), Er<!8;{?  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), [s~6,wz  
nStartPos,nEndPos,i); x+,:k=JMT  
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); TECp!`)j"  
fileSplitterFetch.start(); |eP5iy wg  
} FR6 PY  
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 'oF('uR  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); !Mj28  
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", b$>1_wTL  
nEndPos = " + nFileLength); Lm'+z97  
// fileSplitterFetch[nPos.length-1].start(); oh,29Gg  
=s,}@iqNO4  
? w@)3Z=u  
//等待子线程结束 & DhdB0Hjf  
//int count = 0; .T#}3C/  
//是否结束while循环 E*d UJ.>  
boolean breakWhile = false; !3 zN [@w,  
Ceew~n{  
rYrvd[/*&(  
while(!bStop) %g~zE a-g  
{ \/R $p  
write_nPos(); 0t6DD  
Utility.sleep(500); Te7xj8<  
breakWhile = true; =!IoL7x  
_a  zJ>  
mi@ni+2Tn  
for(int i=0;i<nStartPos.length;i++) !JA//{?  
{ Qn)AS1pL+  
if(!fileSplitterFetch.bDownOver) &A~hM[-  
{ hY|-l%2f  
breakWhile = false; e;9x%kNs!  
break; Mt&n|']`8  
} M# cJ&+rP  
} gPIl:, d(  
if(breakWhile) m[s$)-T  
break; DC2[g9S>8@  
6bT>x5?  
T%w5%{dqJ  
//count++; Y-~ M kB  
//if(count>4) =-/sB>-C  
// siteStop(); ;3+_aoY  
} bmO(tQS$5  
r\FduyOXv  
qD,/Qu62  
System.err.println("文件下载结束!"); Dw<bLSaW&  
} xMFEeSzl>S  
catch(Exception e){e.printStackTrace ();} sCE%./h]  
} g1)ZjABV  
{TaYkuWS  
F[>Y8e<[  
//获得文件长度 >S]"-0tGD=  
public long getFileSize() D+{& zo  
{ ba^/Ar(B  
int nFileLength = -1; \6%`)p  
try{ 6_>(9&g`zV  
URL url = new URL(siteInfoBean.getSSiteURL()); 2Mj_wc   
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); M"yOWD~s~  
httpConnection.setRequestProperty("User-Agent","NetFox"); o,{]<Sm  
me$nP}%C&  
'u6n,yRm  
int responseCode=httpConnection.getResponseCode(); a&u!KAQ  
if(responseCode>=400) _}tPtHPa/  
{ B(Er/\-@U  
processErrorCode(responseCode); HJt '@t=Ak  
return -2; //-2 represent access is error ,>Dpt <  
} }H|'W[Q.  
=ba1::18  
5-UrHbpCZ#  
String sHeader; &FWz7O>1  
DC0O N`  
?*'0;K13  
for(int i=1;;i++) Ru4M7 %  
{ u@t~*E5BpM  
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); >v )V2,P -  
//Utility.log(in.readLine()); < Df2  
sHeader=httpConnection.getHeaderFieldKey(i); \=Od1i  
if(sHeader!=null) 8L5O5F'  
{ gObafIA  
if(sHeader.equals("Content-Length")) K|=va>   
{ ~U5Tn3'~  
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); S }qGf%  
break; 15d'/f  
} -K/c~'%'*  
} f6 s .xQ  
else M"6J"s  
break; hx ^l  
} 0bOT&Z^  
} ua,!kyS  
catch(IOException e){e.printStackTrace ();} #44}Snz  
catch(Exception e){e.printStackTrace ();} QwL*A `@  
M5 ^qc  
z>)lp$  
Utility.log(nFileLength); `nY.&YT  
1'|gxYT  
NdrR+t^#  
return nFileLength; lv+: `   
} uZ'(fnZ$  
^DVryeLD  
e$E>6Ngsr  
//保存下载信息(文件指针位置) jwSPLq%  
private void write_nPos() p-H}NQ\  
{ T[MDjhv'  
try{ a*uG^~ ).  
output = new DataOutputStream(new FileOutputStream(tmpFile)); 1\nzfxx  
output.writeInt(nStartPos.length); ^ 4*#QtO  
for(int i=0;i<nStartPos.length;i++) s"p\-Z  
{ W)8Pq9Hnv  
// output.writeLong(nPos); TeFi[1  
output.writeLong(fileSplitterFetch.nStartPos); 4gZ)9ya   
output.writeLong(fileSplitterFetch.nEndPos); \["I.gQ  
} b*ja,I4  
output.close(); ;te( {u+  
} T8d=@8g,%  
catch(IOException e){e.printStackTrace ();} Dw$RHogb~y  
catch(Exception e){e.printStackTrace ();} g!OcWy)7  
} `26.+>Z7  
bz.sWBugR  
-]{ _^  
//读取保存的下载信息(文件指针位置) XB B>"  
private void read_nPos() BPm" )DMo  
{ 4'`H H  
try{ N9s.nu  
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); xg8R>j  
int nCount = input.readInt(); ma!C:C9#J  
nStartPos = new long[nCount]; f`_{SU"3  
nEndPos = new long[nCount]; %d40us8E  
for(int i=0;i<nStartPos.length;i++) {d]B+'  
{ QDVSFGwr  
nStartPos = input.readLong(); 7FD,TJs  
nEndPos = input.readLong(); hl] y):  
} ,-8Xb+!8I  
input.close(); fY?:SPR+  
} R y(<6u0  
catch(IOException e){e.printStackTrace ();} !VsdKG)  
catch(Exception e){e.printStackTrace ();} ~ 4Mz:h^  
} s&Al4>}.f  
r`.Bj0  
>j*0fb!:]  
private void processErrorCode(int nErrorCode) F 9d6#~  
{ %s9*?6  
System.err.println("Error Code : " + nErrorCode); 1 3)6p|6x  
} 9ZR"Lo>3e+  
*uP;rUY  
%++S;#)~  
//停止文件下载 Aq7`A^1t$  
public void siteStop() .F2"tt?'  
{ {7MY*&P$,  
bStop = true; >Q^ mR  
for(int i=0;i<nStartPos.length;i++) o4@d,uIw^  
fileSplitterFetch.splitterStop(); W(?J,8>  
6c27X/'Z  
lbw+!{Ch  
} "}ur"bU1  
} x1STjI>i  
//负责部分文件的抓取 mA_EvzXk\  
**FileSplitterFetch.java n "^rS}Y]  
*/ 4>fj @X(3  
package NetFox; m!!;CbPo  
k>8OxpaWv?  
*f{4 _ts  
import java.io.*; p]?eIovi  
import java.net.*; WE_'u+!B  
8wZ $Hq  
7}~nQl2  
public class FileSplitterFetch extends Thread { YcR: _ac  
~k?t  
45iO2W uur  
String sURL; //File URL ,zH\P+*  
long nStartPos; //File Snippet Start Position 0}'/pN>  
long nEndPos; //File Snippet End Position 3UZ_1nY  
int nThreadID; //Thread's ID 1rU\ !GfR  
boolean bDownOver = false; //Downing is over =,i?8Fuz  
boolean bStop = false; //Stop identical eb,QT\/G  
FileAccessI fileAccessI = null; //File Access interface ^L Xr4  
W?.xtQEv  
mz;ExV16  
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException z~v-8aw  
{ {l_D+B;  
this.sURL = sURL; [xDIK8d:I  
this.nStartPos = nStart; {_z6  
this.nEndPos = nEnd; sk~7"v{Y.  
nThreadID = id; W=|'&UU Ul  
fileAccessI = new FileAccessI(sName,nStartPos);//定位 IBNb!mPu%  
} y^kC2DS   
#-R]HLW*  
~{kA;uw  
public void run() W&Xi &[Ux  
{ r8FAV9A  
while(nStartPos < nEndPos && !bStop) !}1l8Y  
{ ?6I`$ &OA  
I>-}ys`[  
gq~`!tW'  
try{ [`KQ \4u  
URL url = new URL(sURL); OT)`)PZ"  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection ();  TLVfu4  
httpConnection.setRequestProperty("User-Agent","NetFox"); p{SIGpbR&  
String sProperty = "bytes="+nStartPos+"-"; 6+PP(>em  
httpConnection.setRequestProperty("RANGE",sProperty); [r'hX#  
Utility.log(sProperty); "e29j'u!*  
)coA30YR  
.Dr7YquW  
InputStream input = httpConnection.getInputStream(); }JT&lyO< b  
//logResponseHead(httpConnection); l|9'l[}&  
YsO`1D  
do%.KIk  
byte[] b = new byte[1024]; :n x;~f  
int nRead; u9+)jN<Yh  
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) )*o) iN 7l  
{ j{zVVT  
nStartPos += fileAccessI.write(b,0,nRead); ~i}/  
//if(nThreadID == 1) tfe'].uT  
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); ?C6`  
} !W=2ZlzS  
FOcDBCrOe  
I+Fr#1  
Utility.log("Thread " + nThreadID + " is over!"); `]Vn[^?D  
bDownOver = true; o%Qn%gaX  
//nPos = fileAccessI.write (b,0,nRead); a1weTn*  
} 2Ju,P_<dt  
catch(Exception e){e.printStackTrace ();} OQT i$2  
} |C t Q  
} $g#d1u0q  
rO1.8KKJ  
r1$x}I#Zv  
//打印回应的头信息 <5sfII  
public void logResponseHead(HttpURLConnection con) -%t8a42  
{ Y XxWu8  
for(int i=1;;i++)  6AmFl<  
{ [3W+h1  
String header=con.getHeaderFieldKey(i); "QY~V{u5  
if(header!=null) Szlww  
//responseHeaders.put(header,httpConnection.getHeaderField(header)); UAdj [m61  
Utility.log(header+" : "+con.getHeaderField(header)); /bqJ6$  
else /3~}= b  
break;  aK9zw  
} h6(L22Hn  
} z.kBQ{P  
VH.}}RS%  
u+8?'ZT,  
public void splitterStop() t]pJt  
{ C6b(\#g(  
bStop = true; c1_?Z  
} 9M-/{D^+<  
e9?y0vT//  
yAVt[+0  
} %] 7.E  
z[_Gg8e  
R )e^H  
/* H\e<fi%Q  
**FileAccess.java :y[tZ&*<_?  
*//文件访问(定位,写) px_%5^zRQ  
package NetFox; z3-AYQ.H  
import java.io.*; MT@Uu  
S8Yh>j8-  
aw/5#(1R  
public class FileAccessI implements Serializable{ Eh f{Kl  
n?A;'\cK  
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 ZpY"P6  
RandomAccessFile oSavedFile; K3t^y`z  
long nPos; L"!BN/i_  
9Uh nr]J.  
:YZMR JL  
public FileAccessI() throws IOException \>-%OcYlM  
{ bwh.ekf8  
this("",0); PK* $  
} yf6&'Y{  
b}r3x&)  
[t`QV2um  
public FileAccessI(String sName,long nPos) throws IOException nS1 D&;#Y  
{ >j$CM:w  
oSavedFile = new RandomAccessFile(sName,"rw"); BK]q^.7+:  
this.nPos = nPos; sxLq'3(  
oSavedFile.seek(nPos); /fc@=CO  
} }mC-SC)oSi  
%fz!'C_4  
`4 A%BKYB  
public synchronized int write(byte[] b,int nStart,int nLen) 4<&`\<jZ  
{ %/&?t`%H  
int n = -1; u|D_"q~+6  
try{ I(Yyg,1Z  
oSavedFile.write(b,nStart,nLen); *^u5?{$l(  
n = nLen; Tce2]"^;  
} y(8AxsROp  
catch(IOException e) R@r"a&{/  
{ y85/qg) H^  
e.printStackTrace (); 5 !G}*u.  
} /wL}+  
7 0:a2m  
S:Ne g!`  
return n; :_Y@,CpIEg  
} fNx3\<~V=  
eVDI7W:(Sn  
pVt8z|p_;{  
} b^\u P  
|,Y(YSg.  
xS`>[8?3<T  
/* ^60BQ{ne  
**SiteInfoBean.java iFW)}_.  
*/ Q': }'CI  
package NetFox; ^l6q  
?y7x#_Exc  
`2?9eXC  
public class SiteInfoBean { :'!,L0I|t  
kQ~*iY  
$aX}i4F  
private String sSiteURL; //Site's URL BXVmt!S5F  
private String sFilePath; //Saved File's Path Sf)VQ5U!Y  
private String sFileName; //Saved File's Name 2mbZ6'p {  
private int nSplitter; //Count of Splited Downloading File 4*_9Gl  
M yr [  
=LS?:Mhm  
public SiteInfoBean() jyf[O -  
{//nSplitter的缺省值为5 Qd 1Q~PBla  
//default value of nSplitter is 5 ]dc^@}1bN  
this("","","",5); &V[m{.  
} q7C>A`w  
XU .FLNe  
WLEjRx  
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) RJ1 Q.o  
{ -1~bWRYq  
sSiteURL= sURL; Mjrl KI}f/  
sFilePath = sPath; $z]gy]F  
sFileName = sName; Cw`v\ 9  
this.nSplitter = nSpiltter; E3y"  
g&H6~ +\  
ewSFB< N  
} T"XP`gk  
G_g~-[O  
J A ]s  
public String getSSiteURL() auqM>yx  
{ ao<@a{G  
return sSiteURL; BM#cosV7%h  
} UfSWdR)  
j9sf~}D>  
[: X  
public void setSSiteURL(String value) *BT-@V.4  
{ ojzO?z  
sSiteURL = value; 2![.Kbqa%  
} 6yKr5tH4  
6e$(-ai  
wGE:U`  
public String getSFilePath() cejSGsW6q  
{ C XZm/^  
return sFilePath; n0kBLn  
} NWSBqL5v   
q3B#rje>h  
 [ottUS@  
public void setSFilePath(String value) O2?ye4uq  
{ ._"U{ f2V  
sFilePath = value; ](4V 3w.  
}  ;OQ{  
|0ahvsrtW  
Funep[rA  
public String getSFileName() 3HC aZ?Ry'  
{ v&%GK5j7O  
return sFileName; ] FvN*@lG  
} ? r=cLC  
Sve~-aG  
H?8KTl=e  
public void setSFileName(String value) JNRG [j  
{ r@0HqZx`  
sFileName = value; ]QM6d(zDA  
} )Fk%, H-1  
=9GL;z:R+  
0Np }O=>  
public int getNSplitter() 9`+c<j4/B  
{ Uwr inkoeE  
return nSplitter; *[(O&L&0  
} &Jv j@,>$d  
^)conSm  
5V4Ze;K  
public void setNSplitter(int nCount) z,[4 BM  
{ |AW[4Yn>  
nSplitter = nCount; P*XLm  
} K_',Gd4L  
} V6?ku6k  
$%"i|KTsv:  
1 e1$x@\\  
/* IL?3>$,  
**Utility.java gYfN ?A*`_  
*/ v_"p)4&'  
package NetFox; 8MGtJ'.  
{3]g3mj  
hWwh`Vw%  
public class Utility { 1+v&SU  
*<#jr  
4:=']C  
public Utility() Tk9u+;=6$  
{ >nkd U  
MQY^#N  
L"A,7@:Vd  
} a33}CVG-e3  
',?v7&  
//线程睡眠 kXA o+l  
public static void sleep(int nSecond) aErms-~  
{ \,i9m9;y  
try{ aG}ju;  
Thread.sleep(nSecond); : I28Zi*  
} ao#{N=mn  
catch(Exception e) s\,F 6c  
{ gEbe6!; q3  
e.printStackTrace (); a H'iW)  
} QpwOrxI}  
} 6 uW?xB9  
,J"6(nk  
//日志 EFu2&P  
public static void log(String sMsg) &WE|9  
{ j1%o+#df  
System.err.println(sMsg); d76k1-m\o  
} l9"0Wu@_x  
3~}G~ t  
[URo#  
public static void log(int sMsg) hC?:XVt  
{ $As;Tvw.  
System.err.println(sMsg); @ |v4B[/  
} u~7mH  
} xV[X#.3  
OF&{mJH"g'  
xQ9P'ru  
/* M?Tb9c?`  
**TestMethod.java T_|%n F-+  
*/ %bgjJ`  
package NetFox; "i_I<?aGB  
~+}w>jIm{|  
S#6{4x4  
public class TestMethod { Fxdu)F,~u  
qk;*$Q  
u+UtvzUC  
public TestMethod() b}< T<  
{ ///xx/weblogic60b2_win.exe x.CUJ^_.  
try{ q`_d>l  
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); (+ q#kKR  
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); >=BH$4Ce  
SiteFileFetch fileFetch = new SiteFileFetch(bean); 2K4Jkyi  
fileFetch.start(); b<>GF-`w  
} :kz*.1  
catch(Exception e){e.printStackTrace ();} _^;+_6&[  
GOuBNaU {  
U>?q|(u  
} m/RX~,T*v&  
a~E@scD  
Qn'Do4Le  
public static void main(String[] args) NC'+-P'y  
{ Z&9MtpC+N3  
new TestMethod(); 1$T;u~vg  
} k=1([x  
}  al/Mgo  
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