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http断点续传简单实现(java)

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/* =kW7|c5Z  
**SiteFileFetch.java  OJ# d  
*/ e yByAT~W,  
package NetFox; 6l(HD([_p  
import java.io.*; 0ol*!@?  
import java.net.*; _/}/1/y$Y  
io$fL_R=  
$viZ[Lu!m  
public class SiteFileFetch extends Thread { yzL6oU-{&  
u5P2*  
f5t/=/6>F  
SiteInfoBean siteInfoBean = null; //文件信息Bean y>JSo9[@  
long[] nStartPos; //开始位置 0 SDyE  
long[] nEndPos; //结束位置 @ql S #(  
FileSplitterFetch[] fileSplitterFetch; //子线程对象 HUGhz  
long nFileLength; //文件长度 ",45p@  
boolean bFirst = true; //是否第一次取文件 vSJ# }&  
boolean bStop = false; //停止标志 ;c#jO:A5  
File tmpFile; //文件下载的临时信息 x?G"58  
DataOutputStream output; //输出到文件的输出流 IKeO&]k  
f2M}N  
//负责整个文件的抓取,控制内部线程(FileSplitterFetch类) 6"c(5#H  
public SiteFileFetch(SiteInfoBean bean) throws IOException WP? AQD  
{ 1n>(CwLG"  
siteInfoBean = bean; ^r 9  
//tmpFile = File.createTempFile ("zhong","1111",new File(bean.getSFilePath())); EUuk%<q7C(  
tmpFile = new File(bean.getSFilePath()+File.separator + bean.getSFileName()+".info"); WQltUaF  
if(tmpFile.exists ()) ggzcANCD<  
{ AKUmh  
bFirst = false; ZcrFzi  
read_nPos(); qL!pDZk  
} 1xb1?/n1#  
else X:OUu;  
{ N?mQ50o~C  
nStartPos = new long[bean.getNSplitter()]; .arWbTR)~U  
nEndPos = new long[bean.getNSplitter()]; sK|+&BC  
} "l-R|>6~  
OP\m~1  
mq oB]H,  
nW_cjYS%  
} I73=PfS:m  
LVBE+{P\5?  
T5+9#  
public void run() w@hbY:Z9z  
{ K\^S>dV  
//获得文件长度 .]K{8[:hq  
//分割文件 X32{y973hT  
//实例FileSplitterFetch %1kIaYZ  
//启动FileSplitterFetch线程 <2fgao&-n  
//等待子线程返回 7NQEnAl  
try{ a/lTQj]A  
if(bFirst) %bgUU|CdA  
{ 7toDk$jJRg  
nFileLength = getFileSize(); eIt<da<G?  
if(nFileLength == -1) 7E\k97#G  
{ 2X@"#wIg  
System.err.println("File Length is not known!"); Hie  
} ?!$:I8T  
else if(nFileLength == -2) }9 I,p$  
{ o9c?)KQ  
System.err.println("File is not access!"); 9wP,Z"  
} I*l y 7z  
else R b=q #  
{ k[]2S8K2  
for(int i=0;i<nStartPos.length;i++) ix_&<?8  
{ ~ qezr\$2  
nStartPos = (long)(i*(nFileLength/nStartPos.length)); CjUYwAy$k  
} Yp;?Zq9  
for(int i=0;i<nEndPos.length-1;i++) 7Nlk:f)*-  
{ >AUzsQ  
nEndPos = nStartPos[i+1]; `z<I<  
} 2 UPG8]  
nEndPos[nEndPos.length-1] = nFileLength; \MB$Cwc  
} RZqou|ki  
} 6l& ,!fd  
(A\\s$fE/1  
L_R(K89w  
//启动子线程 o'|B|oZ  
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; DN;3VT.-  
for(int i=0;i<nStartPos.length;i++) z?'z{+HY  
{ "g&hsp+i"A  
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), wg]VG,  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), Oc%W_Gb7  
nStartPos,nEndPos,i); *apkw5B}C  
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); CK(`]-q>,  
fileSplitterFetch.start(); ]Yk)A.y  
} "*ww>0[  
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), "WzD+<oL  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); -nDY3$U/  
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", b>L?0p$ej  
nEndPos = " + nFileLength); r&Qq,koE  
// fileSplitterFetch[nPos.length-1].start(); 7(C:ty9  
9G^gI}bY  
yVgHu#?PM  
//等待子线程结束 40HhMTZ0-  
//int count = 0; EjP9/V G@=  
//是否结束while循环 c]R27r E  
boolean breakWhile = false;  N}KL'  
t_jnp $1m  
Ar'k6NX  
while(!bStop) >1RL5_US  
{ '>[Ut@lT;  
write_nPos(); %'.3t|zH  
Utility.sleep(500); zQaD&2 q  
breakWhile = true; -|4 Oq  
R$i-%3  
)8;At'q}  
for(int i=0;i<nStartPos.length;i++) ~9n30j%]s  
{ L"}tJM.d  
if(!fileSplitterFetch.bDownOver) H7(D8.y )  
{ zV8{|-2]No  
breakWhile = false; z"f+;1  
break; vF1Fcp.@  
} #|=Q5"wU  
} I %|;M%B  
if(breakWhile) "D'"uMS`H  
break; 61](a;Di  
zJo?,c  
F(|XJN  
//count++; H:cAORLB  
//if(count>4) %a']TX  
// siteStop(); k{D0&  
} ZP '0=  
m}6Jdt'|  
-`UOqjb]3  
System.err.println("文件下载结束!"); "v/Yw'! )  
} P|t2%:_  
catch(Exception e){e.printStackTrace ();} o+Fm+5t;  
} Ako]34Rl,  
IYv.~IQO  
CV)K=Br5&_  
//获得文件长度 a9NIK/9  
public long getFileSize() "EwzuM8 f  
{ 8J:=@X^}  
int nFileLength = -1; % _nmv  
try{ D~n-;T  
URL url = new URL(siteInfoBean.getSSiteURL()); d .%2QkL  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); /  QT>"  
httpConnection.setRequestProperty("User-Agent","NetFox"); P=l 7m*m  
*P8CzF^>\&  
[,(+r7aB  
int responseCode=httpConnection.getResponseCode(); AkCy C1  
if(responseCode>=400) AG><5 }  
{ 6sG5 n7E-A  
processErrorCode(responseCode); 6j95>}@  
return -2; //-2 represent access is error }42Hhu7j  
} RK=Pm7L:`y  
8:[ l1d86  
HuR774f[  
String sHeader; 3)I]bui  
uU%Z%O  
?TJ4L/"(k6  
for(int i=1;;i++) >Y(JC#M;  
{ o`G6!  
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); E\TWPV'/  
//Utility.log(in.readLine()); "Mz#1Laby`  
sHeader=httpConnection.getHeaderFieldKey(i); ;hF}"shJN  
if(sHeader!=null) ;YSe:m*  
{ p=3t!3  
if(sHeader.equals("Content-Length")) X}Om)WCr  
{ 4ETHaIiWp  
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); #<X4RJ  
break; JI  cm$  
} [XttT  
} <v/aquLN  
else g/}d> 6  
break; ^VW]Qr!  
} Bh'!aipk  
} &xA>(|a\&-  
catch(IOException e){e.printStackTrace ();} vxOnv8(  
catch(Exception e){e.printStackTrace ();} (E7"GJ  
&nwS7n1eb  
pU'${Z~b  
Utility.log(nFileLength); M?DZShkV_  
EV-sEl8ki  
_>BYUPY  
return nFileLength; bDudETl  
} v(GnG  
}a#T\6rY  
||fw!8E  
//保存下载信息(文件指针位置) Ghc U ~  
private void write_nPos() bRrS d:e  
{ v_Df+  
try{ *JfGGI_E  
output = new DataOutputStream(new FileOutputStream(tmpFile)); L>mM6$l  
output.writeInt(nStartPos.length); v9FR  
for(int i=0;i<nStartPos.length;i++) ,]nRnI^  
{ ''D7Bat@  
// output.writeLong(nPos); ." gq[0_YS  
output.writeLong(fileSplitterFetch.nStartPos); j}d):3!  
output.writeLong(fileSplitterFetch.nEndPos); mZc;n.$U  
} _|W&tB *  
output.close(); ?iV}U  
} dQ~GE}[  
catch(IOException e){e.printStackTrace ();} 'wtb"0 }  
catch(Exception e){e.printStackTrace ();} {&XTa`C  
} tzfyS#E  
B9[vv;lzu  
~cyKPg6  
//读取保存的下载信息(文件指针位置)  ^#C+l  
private void read_nPos() U;TS7A3  
{ |d-x2M[  
try{ xQU//kNL  
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); H }]Zp  
int nCount = input.readInt(); H C,5j)1  
nStartPos = new long[nCount]; d}tmZ*q  
nEndPos = new long[nCount]; 4n@>gW  
for(int i=0;i<nStartPos.length;i++) uD?RL~M  
{ \At~94  
nStartPos = input.readLong(); .ahY 1CO  
nEndPos = input.readLong(); >N2kWSa  
} ^;h\#S[%  
input.close();  :\'1x  
} 5z9hcQAS  
catch(IOException e){e.printStackTrace ();} p`rjWpH  
catch(Exception e){e.printStackTrace ();} f3qR7%X?  
} Er|&4-9  
&bfM`h'  
qo 7<g*kf~  
private void processErrorCode(int nErrorCode) Mpyza%zj  
{ !/tV}.*  
System.err.println("Error Code : " + nErrorCode); g!' x5#]n  
} y9]7LETv\M  
8{!|` b'f  
{D^ )% {  
//停止文件下载 ULu@"  
public void siteStop() k{lo'  
{ w'A*EWO  
bStop = true; V6](_w!  
for(int i=0;i<nStartPos.length;i++) :RukW.MR  
fileSplitterFetch.splitterStop(); lK7:qo  
}~=<7|N.  
@%2crJnkS  
} A'7Y{oPHX  
} $H.U ~  
//负责部分文件的抓取 WRkuPj2  
**FileSplitterFetch.java W( sit;O  
*/ :h(3Ep  
package NetFox; B Tj1C  
H_3Wx fO  
;<[!;8  
import java.io.*; /DH`7E  
import java.net.*; OmZZTeGg1s  
iG"v  
.sQV0jF{  
public class FileSplitterFetch extends Thread { !`7evV:  
ME]7e^  
:|S[i('  
String sURL; //File URL f. >[ J  
long nStartPos; //File Snippet Start Position mt0v (  
long nEndPos; //File Snippet End Position "N_@q2zF  
int nThreadID; //Thread's ID ## vP(M$  
boolean bDownOver = false; //Downing is over e 2N F.  
boolean bStop = false; //Stop identical Fw(  
FileAccessI fileAccessI = null; //File Access interface eYoc(bG(+  
0vDvp`ie#4  
roAHkI  
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException 2B6u) 95  
{ *^7^g!=z2  
this.sURL = sURL; |}e"6e%  
this.nStartPos = nStart; uEr.LCAS  
this.nEndPos = nEnd; R\n@q_!`X  
nThreadID = id; W7~_XI  
fileAccessI = new FileAccessI(sName,nStartPos);//定位 <3tf(?*,k]  
} SJO*g&duQ  
z=>PjIW  
>k@{NP2b  
public void run() C" `\[F`.k  
{ il{x?#Wrb  
while(nStartPos < nEndPos && !bStop) /8`9SS  
{ @>~S$nw/  
UHi^7jQ  
P| ?nx"c  
try{ qFDy)4H)  
URL url = new URL(sURL); #')] ~Xa  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); U v>^ Z2  
httpConnection.setRequestProperty("User-Agent","NetFox"); Yz0HB EA  
String sProperty = "bytes="+nStartPos+"-"; PIFZ '6gn  
httpConnection.setRequestProperty("RANGE",sProperty); JUDZ_cGr  
Utility.log(sProperty); Bs`='w%7  
.3Smqwm=Y  
>b3IZ^SB#$  
InputStream input = httpConnection.getInputStream(); )PU\|I0|)e  
//logResponseHead(httpConnection); v [x 5@$  
jL4"FTcE]3  
s:,fXg25J  
byte[] b = new byte[1024]; _3f/lG?&-  
int nRead; #&S<{75A  
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) <>-gQ9  
{ .g}Y! l  
nStartPos += fileAccessI.write(b,0,nRead); 93w$ck},?G  
//if(nThreadID == 1) ci(BPnQ  
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); (lYC2i_b#  
} ^H<VH  
YWi Y[  
3+U2oI:I  
Utility.log("Thread " + nThreadID + " is over!"); j.c4  
bDownOver = true; ;yZY2)L   
//nPos = fileAccessI.write (b,0,nRead); d]=>U^K  
} T~}g{q,tR  
catch(Exception e){e.printStackTrace ();} B]7QOf"  
} "6?Y$y/wm  
} ]Qx-f* D6  
RhjU^,%  
;Oqbfl#%  
//打印回应的头信息 q>#P|  
public void logResponseHead(HttpURLConnection con) ,Qe`(vU*s  
{ aO\@5i_r  
for(int i=1;;i++) _&@cU<bdee  
{ i2Gh!5]f  
String header=con.getHeaderFieldKey(i); jN7Z} 1`  
if(header!=null) a9nXh6  
//responseHeaders.put(header,httpConnection.getHeaderField(header)); xU9^8,6  
Utility.log(header+" : "+con.getHeaderField(header)); &gm/@_  
else +n8,=}  
break; N_.`5I;e  
} `jDmbD +=  
} {y:+rh&  
N sSl|m  
f6HDfJmE  
public void splitterStop() N%?8Bm~dP  
{ gJ Z9XLPC  
bStop = true; P$;_YLr  
} Tj=g[)+K  
h"Q&E'0d  
=G<S!qW  
} Tq >?.bq9  
:cTwp K  
=CO#Q$  
/* d4-cZw}+  
**FileAccess.java ~E7=c3:"  
*//文件访问(定位,写) r+Y]S-o:  
package NetFox; 8,(5Q  
import java.io.*; .J|" bs9  
^`!EpO>k9  
V|dKKb[Lve  
public class FileAccessI implements Serializable{ '^M3g-C[Jg  
b*qC  
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 K<tkNWasQ  
RandomAccessFile oSavedFile; 8DNGqaH;dt  
long nPos; $yg}HS7HC  
nbz?D_  
ma26|N5  
public FileAccessI() throws IOException )u'("  
{ }vdhk0  
this("",0); /!0{9F<  
} =zW.~(c{  
f_Q_qckB%x  
J;BG/VI1  
public FileAccessI(String sName,long nPos) throws IOException enJE#4Z5&s  
{ /ZKO\q  
oSavedFile = new RandomAccessFile(sName,"rw"); T|[ o  
this.nPos = nPos; Y 1vSwS%{T  
oSavedFile.seek(nPos); l*yJU3PW  
} /CN^">|_  
.Su9fj y%  
SQbnn"  
public synchronized int write(byte[] b,int nStart,int nLen) yN~: 3  
{ Lw.N3!e[  
int n = -1; l2!4}zI2  
try{ m/0t; cx  
oSavedFile.write(b,nStart,nLen); `795 K8  
n = nLen; QJ s /0iw  
} X"{s"Mc0G  
catch(IOException e) l4d2 i;4BK  
{ u37@9  
e.printStackTrace (); &sQtS  
} `W[oLQ  
]7^YPFc+  
ef!V EtEOv  
return n; !g~xn2m$R  
} ~z!U/QR2  
@Tr8.4  
vf(\?Js ,  
} kqA`d  
=GjxqIv  
)vk$]<$  
/* t <#Yr%a  
**SiteInfoBean.java 7@Qz  
*/ mOyBSOad4  
package NetFox; ,.f GZ4  
*, o)`  
W6~B~L  
public class SiteInfoBean { |k> _ jO  
pFD L5  
C sn"sf  
private String sSiteURL; //Site's URL 810u +%fu  
private String sFilePath; //Saved File's Path Zcv1%hI  
private String sFileName; //Saved File's Name pXCmyLQ  
private int nSplitter; //Count of Splited Downloading File >+fet ,  
dM7-,9Vc  
[>4Ou^=1  
public SiteInfoBean() U w][U  
{//nSplitter的缺省值为5 nYMdYt04sl  
//default value of nSplitter is 5 R b6` k^  
this("","","",5); )}7rM6hv  
} X'WbS  
'zZN]P  
q!9SANTx  
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) R y0n_J:7  
{ zrG&p Z  
sSiteURL= sURL; _Y*]'?g`  
sFilePath = sPath; Q5/".x^@  
sFileName = sName; 5B@+$D[0?3  
this.nSplitter = nSpiltter; o|AV2FM)  
b4s.`%U  
Z@ * ^4Ve  
} FU~ Ip  
izow=}  
+^!&-g@(  
public String getSSiteURL() >ZuWsA0q  
{ N%:QaCZKw  
return sSiteURL; 4r5?C;g  
} zN {'@B  
gz-}nCSi  
Y+sycdq  
public void setSSiteURL(String value) ">lu8F  
{ ;2-,Xzz8  
sSiteURL = value; Q'&oSPXSDd  
} p0UR5A>p  
Edc<  8-  
HkD6aJ:kA!  
public String getSFilePath() }i ./,  
{ <MI>>$seiJ  
return sFilePath; \;}F6g  
} u)M dFz  
m49GCo k+  
egxh  
public void setSFilePath(String value) ksT2_Ic  
{ lh&Q{t(+8  
sFilePath = value; M;,Q8z%  
} ]i)m   
,n}X,#]  
xg k~y,F  
public String getSFileName() 1j "/}0fx  
{ r:2G11[  
return sFileName; Zx7Y ,0  
} kFW9@ !9  
\vXo~_-&  
<V#9a83JP  
public void setSFileName(String value) ds,NNN<HW  
{ 9sifc<za  
sFileName = value; "m.jcKt  
} iVLfAN @  
r'#5ncB  
r1yz ?Y_P  
public int getNSplitter() \L-o>O  
{ h.E8G^}@  
return nSplitter; 0 Ji>dr n  
} !v;N@C3C  
O{uc  h  
!jGe_xB}~  
public void setNSplitter(int nCount) ,&rlt+wE  
{ k*d0ws#<l  
nSplitter = nCount; bf|s=,D  
} Jw)Uk< \  
} t23uQR#>b_  
D |kdk;Xv  
//n$#c _}u  
/* Z1 %"w*U  
**Utility.java OOn{Wp  
*/ NKd}g  
package NetFox; U,Ya^2h%  
:*Lr(-N-  
?55t0  
public class Utility { |*ss`W7F,2  
n]^zIe^6  
E1IT>_  
public Utility() YEH /22  
{ p'{B|ujj6  
oJb${k<3  
)voJq\Y)%  
} r#rL~Rsd}  
A[:0?Ez=  
//线程睡眠 P0VXHE1p  
public static void sleep(int nSecond) $`,10uw  
{ *;cvG?V  
try{ :}'5'oVG  
Thread.sleep(nSecond); $p:RnH\H1  
} vy&'A$ H  
catch(Exception e) sG{fxha  
{ ,Ta k',  
e.printStackTrace (); B;x5os  
} (7Su{tq  
} ]!CMo+  
KUJCkwQ  
//日志 )` ~"o*M  
public static void log(String sMsg) 9U~fc U6  
{ :%G_<VAo!  
System.err.println(sMsg); U9"g;t+/   
} a',6WugIP  
{txW>rZX  
by07l5  
public static void log(int sMsg) 'Ur1I "  
{ Ckd j|  
System.err.println(sMsg); 5j'7V1:2  
} ZHu"& &  
} uoJ@Jt'j  
u@&e{w~0  
J9aqmQj('  
/* x[u4>f  
**TestMethod.java 7R5m|h`M  
*/ a]H&k$!c  
package NetFox; ^IQtXae6M  
DVJuX~'|!  
gq%U5J"x;J  
public class TestMethod { e={ ?d6  
BD.&K_AW  
arK(dg~S  
public TestMethod() 3Z0ez?p+5  
{ ///xx/weblogic60b2_win.exe  4,g_$)  
try{ 1S[4@rZ  
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); U:r^4,Mz*  
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); p : {,~ 1  
SiteFileFetch fileFetch = new SiteFileFetch(bean); :m]KVcF.  
fileFetch.start(); ql/K$#u  
} ":v^Y 9  
catch(Exception e){e.printStackTrace ();} B*Z}=$1j  
DpCe_Vb%M  
Fs$mLa  
} tJe5`L  
rX(Ol,&oP  
\jmT#Gt`9  
public static void main(String[] args) d9iVuw0u<  
{ ]hMs:$}  
new TestMethod(); QLxe1[qI  
} .R^R32ln  
} sA~Ijg"6  
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