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http断点续传简单实现(java)

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/* 4O/IT1+A  
**SiteFileFetch.java `xx3JQv[  
*/ &]shBvzl^  
package NetFox; (E,Ibz2G:e  
import java.io.*; h=JW^\?\]  
import java.net.*; >5?:iaq z  
7[UD;&\k  
\ 9iiS(e  
public class SiteFileFetch extends Thread { WW>m`RU`  
Tj{3#?]Ho  
.wyuB;:  
SiteInfoBean siteInfoBean = null; //文件信息Bean $G5:/,Q  
long[] nStartPos; //开始位置 .U44p*I  
long[] nEndPos; //结束位置 S#r|?GYua  
FileSplitterFetch[] fileSplitterFetch; //子线程对象 es~1@Jb  
long nFileLength; //文件长度 3^xq+{\)  
boolean bFirst = true; //是否第一次取文件 +l.LwA  
boolean bStop = false; //停止标志 cc:$$_'L  
File tmpFile; //文件下载的临时信息 < (B|g&A  
DataOutputStream output; //输出到文件的输出流 #S x  
^!0z+M:>^  
//负责整个文件的抓取,控制内部线程(FileSplitterFetch类) E@n~ @|10  
public SiteFileFetch(SiteInfoBean bean) throws IOException . UH'U\M  
{ N u\<Xr8  
siteInfoBean = bean; f-ceDn  
//tmpFile = File.createTempFile ("zhong","1111",new File(bean.getSFilePath())); xSNGf@1b  
tmpFile = new File(bean.getSFilePath()+File.separator + bean.getSFileName()+".info"); c!'\k,ma<9  
if(tmpFile.exists ()) &I(\:|`o  
{ qxsHhyB_n;  
bFirst = false; BW}M/  
read_nPos(); }p?67y/  
} |lg jI!iK  
else }L&LtW{X  
{ 3bR%#G%  
nStartPos = new long[bean.getNSplitter()]; ^SKHYo`,,N  
nEndPos = new long[bean.getNSplitter()]; )rt%.`  
} SMJRoK3  
E`<ou_0N@q  
{K6Z.-.`  
R/*"N'nH-%  
} E*wG5] at  
#z<# oC5  
EtaKo}!A}  
public void run() ! K_<hNG&  
{ E_DQ.!U!o  
//获得文件长度 odC"#Rb  
//分割文件 Xo] 2iQy  
//实例FileSplitterFetch ?6{g7S%  
//启动FileSplitterFetch线程 kS=nH9  
//等待子线程返回 dUt4] ar  
try{ F",TP,X  
if(bFirst) iyd$_CJz  
{ N)AlQ'Lwx  
nFileLength = getFileSize(); VZ =:`)  
if(nFileLength == -1) \E<Qi3W>*  
{ &5${k'  
System.err.println("File Length is not known!"); vt^7:! r  
} sQ,xTWdj  
else if(nFileLength == -2) lX)AbK]nb  
{ k?TZY|_  
System.err.println("File is not access!"); \AH5 zdK  
}  _cj=}!I  
else hliO/3g  
{ ,+4T7 UR  
for(int i=0;i<nStartPos.length;i++) U]_WX(4 @  
{ eEP{?F^I[  
nStartPos = (long)(i*(nFileLength/nStartPos.length)); )KVr2y;RF  
} 5J|S6x\  
for(int i=0;i<nEndPos.length-1;i++) v'b%m8  
{ N3aqNRwlk  
nEndPos = nStartPos[i+1]; @ =~k[o  
} .`5|NUhN  
nEndPos[nEndPos.length-1] = nFileLength; |+::sL\r  
} qNP)oU92  
} N6\rjYx+7  
hf0(!C*  
jC>#`gD  
//启动子线程 D GcpYA.7'  
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; qtozMa  
for(int i=0;i<nStartPos.length;i++) T!B\ixt6  
{ kWVk^ ,  
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), iLNUydiS  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), [ }Tb2|  
nStartPos,nEndPos,i); !<HMMf,-D  
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); SQn.`0HT  
fileSplitterFetch.start(); VjNr<~|d  
} Z"_8 l3  
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), }r,xx{.u7  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); |N"K83_pr  
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", W Zm8!Y  
nEndPos = " + nFileLength); czpu^BT;;T  
// fileSplitterFetch[nPos.length-1].start(); }2"W0ZdWD  
DuR9L'  
CEaAtAM  
//等待子线程结束 E;x-O)(&  
//int count = 0; vYb4&VV  
//是否结束while循环 Xq03o#-p+  
boolean breakWhile = false; 58HA*w  
6Aq]I$  
!rAH@y.l  
while(!bStop) [+pa,^  
{ 'TH[Db'`I  
write_nPos(); o:W*#dt  
Utility.sleep(500); Qg~w 3~  
breakWhile = true; s(5hFuyg  
;CF:cH*  
*pSnEWwE  
for(int i=0;i<nStartPos.length;i++) :{iH(ae;  
{ !#W>x49}  
if(!fileSplitterFetch.bDownOver) ,f>9oOqqA  
{ ncOgSj7e  
breakWhile = false; l&U$L N$*e  
break; 2w8cJadT'p  
} w43b=7  
} ,52 IR[I<T  
if(breakWhile) [f6BA|   
break; amC)t8L?  
Nc{&AV8Y_v  
fxoEK}TM  
//count++; :i?6#_2IC  
//if(count>4) h8 N|m0W  
// siteStop(); Y z&!0Hfd  
} d7[^p N  
%aMC[i  
G$V=\60a-  
System.err.println("文件下载结束!"); `x#S. b  
} P(b[|QF  
catch(Exception e){e.printStackTrace ();} 0RMW>v/7kL  
} 43B0ynagN  
I[ \7Bf  
uGb+ *tD  
//获得文件长度 lGWz  
public long getFileSize() U'(zKqC   
{ 9t)Hi qj  
int nFileLength = -1; *8?2+ )5"  
try{ g`S;xs  
URL url = new URL(siteInfoBean.getSSiteURL()); hx9t{Zi  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); iJ^}{-  
httpConnection.setRequestProperty("User-Agent","NetFox"); rZ3ji(4HS  
0 3v&k  
pgh(~ [  
int responseCode=httpConnection.getResponseCode(); >4Tk#+%Jj  
if(responseCode>=400) DGb1_2ZQ  
{ E]/2 u3p  
processErrorCode(responseCode); .x,y[/[[)  
return -2; //-2 represent access is error IJ2'  
} {TpbUj0  
76@W:L*J$J  
CZ u=/8?  
String sHeader; wzju)qS  
XF)N_}X^  
1~K'r&  
for(int i=1;;i++) B t}90#  
{ jIe /X]  
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ());  S9}I  
//Utility.log(in.readLine()); K'J_AMBL  
sHeader=httpConnection.getHeaderFieldKey(i);  d9k`  
if(sHeader!=null) v9Ii8{ca|  
{ pMHl<HH  
if(sHeader.equals("Content-Length")) k &J;,)V  
{ JfWkg`LqL  
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); axvZA:l  
break; xCXsyZ2h  
} tyW}=xs  
} uuwJ-  
else }lX$KuD  
break; \u[}  
} 7AT8QC`u  
} R3_OCM_*  
catch(IOException e){e.printStackTrace ();} [.xY>\e  
catch(Exception e){e.printStackTrace ();} *w(n%f  
t :YZua  
P8By~f32_  
Utility.log(nFileLength);  2hF^U+I}  
4>V@+#Ec5  
P}5bSQ( a3  
return nFileLength; 1mJUl x  
} 8b]4uI <  
;k`51=Wi  
u3O@ccJ;  
//保存下载信息(文件指针位置)  mih}?oi  
private void write_nPos() ,:L^vG@*  
{ f<wYJGI  
try{ -+1O*L!  
output = new DataOutputStream(new FileOutputStream(tmpFile)); )SJM:E  
output.writeInt(nStartPos.length); 3 5.&!4}  
for(int i=0;i<nStartPos.length;i++) ( `bb1gz  
{ $%DoLpE>  
// output.writeLong(nPos); j]kgdAq>  
output.writeLong(fileSplitterFetch.nStartPos); )GVTa4}p  
output.writeLong(fileSplitterFetch.nEndPos); -F`GZ  
} NN'pBU R  
output.close(); |\uj(|  
} l3F$5n  
catch(IOException e){e.printStackTrace ();} >YWK"~|i~  
catch(Exception e){e.printStackTrace ();} 'pIrwA^6N  
} 4PxP*j  
N7lg6$s Aj  
'a+^= c  
//读取保存的下载信息(文件指针位置) {Dl@/fz  
private void read_nPos() TxF^zx\  
{ K\%\p$ZD  
try{ j3-o}6  
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); & tT6.@kH  
int nCount = input.readInt(); `WL3aI":  
nStartPos = new long[nCount]; ~$K{E[^<  
nEndPos = new long[nCount]; &v((tZ  
for(int i=0;i<nStartPos.length;i++) i *:QbMb  
{ rbdrs  
nStartPos = input.readLong(); N9G xJ6  
nEndPos = input.readLong(); .lb]Xa*n  
} K2x2Y=  
input.close(); `B3-#!2X  
} Izu____  
catch(IOException e){e.printStackTrace ();} d"?"(Q_8n  
catch(Exception e){e.printStackTrace ();} m85ZcyW1T  
} }hg=#*  
myX&Z F_9  
D8,8j;  
private void processErrorCode(int nErrorCode) V;SV0~&  
{ S`5bcxI_  
System.err.println("Error Code : " + nErrorCode); bi+M28m  
} aQL0Sj:,  
8Snv, Lb`^  
A+Isk{d  
//停止文件下载 td%J.&K_*'  
public void siteStop() RRS)7fFm  
{ D`^wj FF  
bStop = true; %/e'6g<  
for(int i=0;i<nStartPos.length;i++) AYY(<b  
fileSplitterFetch.splitterStop(); yW'{Z]09  
[Lje?M* r  
WcSvw  
} Nm&'&L%Ch  
} *cWHl@4  
//负责部分文件的抓取 &PV%=/ -J  
**FileSplitterFetch.java ${z#{c1  
*/ MMKN^a"GA  
package NetFox; V1M|p!  
OW};i|  
meV Z_f/  
import java.io.*; +%9Re5R  
import java.net.*; b`+yNf  
PQl A(v+S  
k%~;mu"4}  
public class FileSplitterFetch extends Thread { Bq)dqLwk  
f:\)! &W  
[n/c7Pe  
String sURL; //File URL DjK7_'7(L  
long nStartPos; //File Snippet Start Position :l]qTCmY  
long nEndPos; //File Snippet End Position n.9k5r@  
int nThreadID; //Thread's ID 3xz~##  
boolean bDownOver = false; //Downing is over W"@'}y  
boolean bStop = false; //Stop identical ~fD\=- S1  
FileAccessI fileAccessI = null; //File Access interface %,vq@..^  
zdPJ>PNU  
T;BFO5G@  
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException Lb Jf5xdi  
{ 2Cy,#X%j>  
this.sURL = sURL; e)?}2  
this.nStartPos = nStart; +$L}B-F  
this.nEndPos = nEnd; m,kYE9 {  
nThreadID = id; p+?`ru  
fileAccessI = new FileAccessI(sName,nStartPos);//定位 l:@=9Fp>  
} ,\ 1X\  
KNN{2thy `  
9teP4H}m  
public void run() 0/] h"5H3  
{ &8i$`6wY  
while(nStartPos < nEndPos && !bStop) `~d7l@6F  
{ \8ZVI98  
A/a=)s u  
2 ^"j]g>mj  
try{ ,(h -  
URL url = new URL(sURL); 1ED7 .#g  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); IfB .2e`  
httpConnection.setRequestProperty("User-Agent","NetFox"); w+ ')wyB  
String sProperty = "bytes="+nStartPos+"-"; YBj*c$.D0  
httpConnection.setRequestProperty("RANGE",sProperty);  yI|x 5f  
Utility.log(sProperty); R%n*wGi_6b  
 ]XlBV-@b  
 "9[2vdSX  
InputStream input = httpConnection.getInputStream(); ;&|I/MVm  
//logResponseHead(httpConnection); -`Z!p  
1mtYap4  
^bPpcm=  
byte[] b = new byte[1024]; AEj%8jh  
int nRead; :+\sKEzL  
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) jcJ@A0]  
{ c oZK  
nStartPos += fileAccessI.write(b,0,nRead); ,aezMbg  
//if(nThreadID == 1) ?QKD YH(  
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); Zbr e5&aU  
}  whw+  
1O0)+9T82  
AfO.D ?4x  
Utility.log("Thread " + nThreadID + " is over!"); T.z efoZ  
bDownOver = true; NL|c5y<r  
//nPos = fileAccessI.write (b,0,nRead); 7P2(q  
} p9G+la~;VM  
catch(Exception e){e.printStackTrace ();} Zp[>[1@+  
} Ii}{{1N6  
} WPr:d  
F(/<ADx  
ul_E{v  
//打印回应的头信息 (p#c p  
public void logResponseHead(HttpURLConnection con) &Hf%Va[B  
{ ddl]! ^IK  
for(int i=1;;i++) CIo`;jt K  
{ Kp7)my  
String header=con.getHeaderFieldKey(i); X4\T=Q?uLx  
if(header!=null) Or$"f3gq  
//responseHeaders.put(header,httpConnection.getHeaderField(header)); v]@ XyF\j8  
Utility.log(header+" : "+con.getHeaderField(header)); T}?b,hNl$  
else T[e+iv<8j  
break; sF :pwI5^  
} g2?W@/pa  
} k t!@}QP  
k9H}nP$F  
rIB./,  
public void splitterStop() on8$Kc  
{ /oEDA^qx  
bStop = true; n4{?Odrf  
} 4IOqSB|  
&x*l{s[  
l{3zlXk3z  
} n?6^j8i  
_?felxG[  
!Y|xu07  
/* )R<93`q  
**FileAccess.java ,@ p4HN*  
*//文件访问(定位,写) ,H?e23G  
package NetFox; a 01s'9Be  
import java.io.*; 89 m.,  
Z3wdk6%:}  
!a V:T&6  
public class FileAccessI implements Serializable{ N@Ap|`Ei  
T:%0i8p  
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 >\'}&oi  
RandomAccessFile oSavedFile; {%('|(57  
long nPos; $!p2Kf>/Q  
@Kt!uKrI  
tr0kTW$Ad  
public FileAccessI() throws IOException =C(BZ+-^  
{ r&v!2A]:  
this("",0); <x<qO=lq  
} J<"Z6 '0v  
&a\w+  
&'/PEOu&}G  
public FileAccessI(String sName,long nPos) throws IOException 3zfiegY@wm  
{ ~3Qa-s;g  
oSavedFile = new RandomAccessFile(sName,"rw"); leSBR,C  
this.nPos = nPos; *h?}~!AjY  
oSavedFile.seek(nPos); cRag0.[  
} rKOa9M  
{='wGx  
n]w%bKc-9  
public synchronized int write(byte[] b,int nStart,int nLen) @pJ;L1sn  
{ X}={:T+6s  
int n = -1; `;R$Ji=>  
try{ ]{|l4e4P  
oSavedFile.write(b,nStart,nLen); w0=/V[fs  
n = nLen; \zA3H$Df~  
} g=v'[JPd  
catch(IOException e) '>bn94$  
{ F|VHr@%  
e.printStackTrace (); i 28TH Jh  
} K",Xe>  
v'`qn  
%,S:^Rvv  
return n; (IHR {m  
} F!I9)PSj  
(?T{^Hg  
N7 _rVcDe  
} &C9)%5 O)  
. Z9c.E{  
%qrUP\rn  
/* 1"<{_&d1  
**SiteInfoBean.java )`|`PB  
*/ / a}N6KUi  
package NetFox; w9x5IRWk  
E 6Uj8]P`  
z+0#H39&  
public class SiteInfoBean { s"tH?m )6  
S?'L%%Vo  
|a\,([aU  
private String sSiteURL; //Site's URL HmsXV_B8[Y  
private String sFilePath; //Saved File's Path @YS,)U)4S  
private String sFileName; //Saved File's Name RSM+si/  
private int nSplitter; //Count of Splited Downloading File m\=Cw&(  
RWDPsZC  
uE,T Ea9;  
public SiteInfoBean() ^MhMYA  
{//nSplitter的缺省值为5 B/~ubw  
//default value of nSplitter is 5 -@'RYY=  
this("","","",5); %vG;'_gM B  
} $`C$|9S  
7D8 pb0`;J  
5Ktll~+:#  
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) `J{{E,y @  
{ @@!]Raj=  
sSiteURL= sURL; `B3YP1  
sFilePath = sPath; 0+_;6  
sFileName = sName; {FC<vx{42  
this.nSplitter = nSpiltter; _39VL  
F Zt;D  
7=wQ#bq"1P  
} -s91/|n  
Ym-mfWo^#  
!;k ^  
public String getSSiteURL() [[4!b E  
{ 3)^ 2X  
return sSiteURL; zJ8jJFL+Y  
} S~g "  
$qoal   
Y\(?&7Aax  
public void setSSiteURL(String value) `RqV\ 6G+  
{ 0V2~  
sSiteURL = value; p+2%LYR u  
} z`dnS]q9  
r6:nYyF$)v  
8rz ,MsFR  
public String getSFilePath() D/2;b;-  
{  )Z:maz  
return sFilePath; OtT*)8*c  
} d5W =?  
U!lWP#m  
R~d Wblv  
public void setSFilePath(String value) EiA_9%<  
{ ar`}+2Qh0  
sFilePath = value; 'HWPuWW  
} 0+rBGk  
@]],H0  
M!PK3  
public String getSFileName() H Mfhe[A?  
{ ^g+M=jq _  
return sFileName; ef:Zi_o   
} !-B|x0fs  
}OgZZ8-_M  
*+ O  
public void setSFileName(String value) o-AAx#@  
{  A1jA$  
sFileName = value; V#DNcF~v]f  
} ev yA#~o  
4Rl~7|  
v)!^%D  
public int getNSplitter() z&|sks7  
{ H)+wkR!~  
return nSplitter; [lj^lN8  
} lR]SGdY  
7<F{a"5P  
1~*JenV-  
public void setNSplitter(int nCount) %bTXu1  
{ *&F~<HC2+  
nSplitter = nCount; 73E[O5?b  
} I9cZZ`vs  
} ~0{F,R.$  
vqwSOh|P9  
G4f%=Z  
/* `]l[p+DO  
**Utility.java {/qq*0wa  
*/ 9q<?xO  
package NetFox; YYd!/@|N5  
g6q67m<h  
"Ze<dB#,Y  
public class Utility { @p7*JLO  
F[oTc^dr  
0^ $6U  
public Utility() F:2V;  
{ }?%5Ae7l,  
n{.SNipU  
}{)>aJ  
} 0hju@&Aa  
AkV8}>G?#A  
//线程睡眠 Y/n],(t)  
public static void sleep(int nSecond) '$be+Z32  
{ =MMSmu5!  
try{ <o_(,,P%  
Thread.sleep(nSecond); :#spL*FIx  
} h@(S];.  
catch(Exception e) P:HmT   
{ dmE.yVI"O  
e.printStackTrace (); ?(j:F2dU~  
} r(/+- t  
} Lc13PTz>>g  
l0{R`G,  
//日志 k /lDE  
public static void log(String sMsg) UxVxnJ_  
{ +S}/ 6dg  
System.err.println(sMsg); ^y&sKO  
} 1bJrEXHXy  
| D,->k  
i}e OWi  
public static void log(int sMsg) x-=qlg&EI  
{ dy2<b+ ..  
System.err.println(sMsg); SH M@H93  
} <bgFc[Z  
} 6 VuMx7W1  
 $"x~p1P  
=!|= Y@  
/* '"Y(2grP  
**TestMethod.java HFrwf{J  
*/ JG!@(lr  
package NetFox; ir3EA'_>N  
G![JRJxQ  
SW_jTn#x  
public class TestMethod { x1R<oB |  
\#)w$O  
Oi4tG&q  
public TestMethod() 5IiZnG u  
{ ///xx/weblogic60b2_win.exe 6.g k6  
try{ dgM@|&9*m  
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); 4z>SI\Ss  
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); 924a1  
SiteFileFetch fileFetch = new SiteFileFetch(bean); H)O I&?  
fileFetch.start(); yMbg1+:   
} ;*XH[>I  
catch(Exception e){e.printStackTrace ();} VRa>bS  
|jE0H!j  
8P3"$2q  
} =F"vL  
z;ko )  
eUE(vn#  
public static void main(String[] args) ,fW%Qv  
{ C{8(ew  
new TestMethod(); z1 P=P%F  
} P+t`Rw  
} Ov PTgiI!N  
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