http断点续传简单实现（java)

/* Vs@H>97,
G  
**SiteFileFetch.java ~Rk~Zn  
*/ 0`%Ask  
package NetFox; CKr5L  
import java.io.*; |++\"g  
import java.net.*; O[<0\  
B"=w9w]  
XCUU(H  
public class SiteFileFetch extends Thread { ^QTtCt^:  
4g^Xe-  
]@9ZUtU,;N  
SiteInfoBean siteInfoBean = null; //文件信息Bean 0mi$_Ld+  
long[] nStartPos; //开始位置 o2e gNTG  
long[] nEndPos; //结束位置 b_rHt s  
FileSplitterFetch[] fileSplitterFetch; //子线程对象 v2;'F  
long nFileLength; //文件长度 dxK3462  
boolean bFirst = true; //是否第一次取文件 P1IL]  
boolean bStop = false; //停止标志 :DoE_  
File tmpFile; //文件下载的临时信息 w-wap  
DataOutputStream output; //输出到文件的输出流 /7jb&f   
m%)Cw)t 7  
//负责整个文件的抓取，控制内部线程（FileSplitterFetch类） II) K0<  
public SiteFileFetch(SiteInfoBean bean) throws IOException m)Sdogt_  
{ nX|]JW  
siteInfoBean = bean; 9A!B|s  
//tmpFile = File.createTempFile ("zhong","1111",new File(bean.getSFilePath())); F0]xc  
tmpFile = new File(bean.getSFilePath()+File.separator + bean.getSFileName()+".info"); LMTz/M  
if(tmpFile.exists ()) uwo\FI  
{ EaU
O
>S  
bFirst = false; #d;/Me  
read_nPos(); 4"~l^yK  
} Z|6,*XEc   
else =Cg1I\  
{ L wP  
nStartPos = new long[bean.getNSplitter()]; ['jr+gIfQ  
nEndPos = new long[bean.getNSplitter()]; -0f,qNF  
} ZYo?b"6A  
Ge+T[  
ibn(eu<uW  
()o[(Hx+ph  
} z6x`O-\  
M~,N~ N1  
&"'Z)iWm  
public void run() uN+]q qCf  
{ "^NsbA+  
//获得文件长度 4I!g?Moh  
//分割文件 Z)'gj  
//实例FileSplitterFetch ne9- c>>  
//启动FileSplitterFetch线程 G;Py%8  
//等待子线程返回 4c9a"v  
try{ r}i}4
K[1  
if(bFirst) 45.Vr[FS.  
{ 8~ wP?  
nFileLength = getFileSize(); pxb4x#CC  
if(nFileLength == -1) 8KMo!p\i  
{ r<c&;*  
System.err.println("File Length is not known!"); |*n B2  
} _:7:ixN[Ie  
else if(nFileLength == -2) kY^ k*-v  
{ "X,*VQl:  
System.err.println("File is not access!"); /_qW?LKG/  
} W*r
1Sy  
else &(X67  
{ +sT S1t  
for(int i=0;i<nStartPos.length;i++) )18C(V-x  
{ ToX--w4  
nStartPos = (long)(i*(nFileLength/nStartPos.length)); Jp"yb`w  
} o1Nfn'!3/>  
for(int i=0;i<nEndPos.length-1;i++) LDh,!5G-M  
{ }*?,&9/_)  
nEndPos = nStartPos[i+1]; Fxv5kho  
} W[<ZI>mf  
nEndPos[nEndPos.length-1] = nFileLength; 3nnoXc'  
} 0)rayzv  
} bYBEh n  
$Ts;o  
i|[**P  
//启动子线程 ],s{%a5wC  
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; X.+|o@G  
for(int i=0;i<nStartPos.length;i++) `!Yd$=*c_&  
{ =z[$o9  
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), %U6A"?To  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), DIw9ov>k  
nStartPos,nEndPos,i); y}1Pc
*  
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); *-(8Z>9  
fileSplitterFetch.start(); 6{!Cx9V  
} DM,)nh6'  
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), kgh0  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); s;cGf+  
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", K5^`,}Q^  
nEndPos = " + nFileLength); "p]!="\  
// fileSplitterFetch[nPos.length-1].start(); 7~Z(dTdSG  
89Ir}bCr  
X& mD/1  
//等待子线程结束 H3LuRGe&2  
//int count = 0; b|e1HCH  
//是否结束while循环 gY!?JZC-0  
boolean breakWhile = false; {5]c\_.  
72ZoN<c  
h"7~`!"~  
while(!bStop) XK&G`cJ[  
{ -2'1KAk-W  
write_nPos(); q_cP<2`@V  
Utility.sleep(500); >&ENrvaJ  
breakWhile = true; 0f#xyS 3  
?Wc+ J4  
[kf6bf@  
for(int i=0;i<nStartPos.length;i++) 9yz@hdG  
{ ?j&ZzK'#^  
if(!fileSplitterFetch.bDownOver)  |A\o  
{ C5g9Gg  
breakWhile = false; ! (Q[[M  
break; $0k7W?tu  
} \/64Xv3L0  
} td7Of(k'  
if(breakWhile) &0i$Y\g  
break; }U'  
mLx=Zes:.  
bYO['ORr@  
//count++; !jvl"+_FV  
//if(count>4) 3CH>!QOA  
// siteStop(); fN/;BT  
} (&Rql7](8  
7>=
 
j WSgO(y  
System.err.println("文件下载结束！"); }Ogb|8  
} bh(}f.@ 9  
catch(Exception e){e.printStackTrace ();} ?)T@qn+  
} @]!9;?so  
6_:I~TTX  
Fv*Et-8tN5  
//获得文件长度 K|Eelhm  
public long getFileSize() D5!#c-Y-  
{ 1_};!5$.  
int nFileLength = -1; 1tLEKSo+  
try{ --EDr>'D5P  
URL url = new URL(siteInfoBean.getSSiteURL()); `NTtw;%Y  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); uW [yNwM  
httpConnection.setRequestProperty("User-Agent","NetFox"); 3b|=V  
Gu@C*.jj!  
E*h!{)z@F  
int responseCode=httpConnection.getResponseCode(); YmpaLZJ  
if(responseCode>=400) JfY(};&  
{ !C h1q  
processErrorCode(responseCode); ,Js-'vX  
return -2; //-2 represent access is error % m"Qg<  
} ,,!P-kK$  
|]9L#  
zk"8mTg  
String sHeader; iCLH  
@]]&^ 7  
9g\;L:'  
for(int i=1;;i++) TyjZ  
{ plp-[eKcD  
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); J.'%=q(Sb  
//Utility.log(in.readLine()); ANNVE},  
sHeader=httpConnection.getHeaderFieldKey(i);
9ln=f=  
if(sHeader!=null) q#@r*hl  
{ ^`B;SSV  
if(sHeader.equals("Content-Length")) =H3tkMoi2  
{ #4JLWg  
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); T:@7EL  
break; k~gOL#$  
} XK\3"`kd  
} Oet+$ b  
else ,<Z,-0S  
break; \7%#4@;?  
} wZN_YFwQ  
} nzaA_^`mB  
catch(IOException e){e.printStackTrace ();} iPkCuLQ}  
catch(Exception e){e.printStackTrace ();} 8\^A;5  
!^ad{#|X  
7BL)FJ]UR]  
Utility.log(nFileLength); TQmrL  
M9afg$;.xe  
DIw_"$'At  
return nFileLength; -U\'Emu4  
} %<x!mE x  
%1$#fxR  
P%H Dz  
//保存下载信息（文件指针位置） Fe4>G8uuwn  
private void write_nPos() Mm(#N/  
{ %1:caa@_p  
try{ -- FzRO{D  
output = new DataOutputStream(new FileOutputStream(tmpFile)); s5rD+g]E`  
output.writeInt(nStartPos.length); &^#u=w?^x  
for(int i=0;i<nStartPos.length;i++) RgA"`p7{  
{ CGzu(@dd\  
// output.writeLong(nPos); 9^ZtbmUf
 
output.writeLong(fileSplitterFetch.nStartPos); ~!!\#IX  
output.writeLong(fileSplitterFetch.nEndPos); w#[cGaIB  
} 3fp&iz  
output.close(); n=bdV(?4  
} 7KX27.~F  
catch(IOException e){e.printStackTrace ();} o{! :N>(  
catch(Exception e){e.printStackTrace ();} ! xG*
W6IT  
} \Dy|}LE  
A+gS'DZ9C  
-F[@)$L  
//读取保存的下载信息（文件指针位置） QF\nf_X  
private void read_nPos() Ei):\,Nv  
{ FOk;=+  
try{ @aZTx/  
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); 9$Z0mzk  
int nCount = input.readInt(); /1v9U|j  
nStartPos = new long[nCount]; KMz!4N  
nEndPos = new long[nCount]; )S(Ly.  
for(int i=0;i<nStartPos.length;i++) XC)9aC@s  
{ *;]}`r  
nStartPos = input.readLong(); }ePl&-9T  
nEndPos = input.readLong(); *=2W:,$  
} ~bxev/$d  
input.close(); 4|E^ #C  
} giX[2`^NG  
catch(IOException e){e.printStackTrace ();} (Jw_2pHxr"  
catch(Exception e){e.printStackTrace ();} 3,Yr%`/5'  
} Uu5(/vw]  
eF22 ~P  
j&oRj6;Ha+  
private void processErrorCode(int nErrorCode) #}FUau$  
{ V(F9=r<X  
System.err.println("Error Code : " + nErrorCode); _OTVQo Ap  
} Bskp&NV':  
.WqqP  
M|K^u.4
 
//停止文件下载 h7!O K  
public void siteStop() DkEv1]6JI_  
{ T1$E][@Iv  
bStop = true; p>;@]!YWQ  
for(int i=0;i<nStartPos.length;i++) =I546($  
fileSplitterFetch.splitterStop(); ;6Yg}L  
LCH\;07V#  
{]<c6*gQ  
} qrYbc~jI7  
} rBNVI;JZW  
//负责部分文件的抓取 <3x%-m+p4  
**FileSplitterFetch.java 32<D9_  
*/ Qk:Lo*!  
package NetFox; JiaR*3#  
#~|k EGt  
P,{Q k~iu  
import java.io.*; PY.K_(D  
import java.net.*; hOUH1m.  
'UIFP#GtFO  
*G> x07S)~  
public class FileSplitterFetch extends Thread { #@$80eFq  

*uhQP47B  
p35=CX`T.  
String sURL; //File URL I[Lg0H8  
long nStartPos; //File Snippet Start Position /;#kV]nF  
long nEndPos; //File Snippet End Position &,k!,<IF  
int nThreadID; //Thread's ID M`H#Qo5/  
boolean bDownOver = false; //Downing is over 78uImC*o  
boolean bStop = false; //Stop identical q2vD)r  
FileAccessI fileAccessI = null; //File Access interface 1N8] ~j  
{,Q)D$i  
phuiLW{&  
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException *9EwZwE_K  
{ Yt]`>C[|D  
this.sURL = sURL; 2!J#XzR0W  
this.nStartPos = nStart; i D IY|  
this.nEndPos = nEnd; I?3b}#&V9  
nThreadID = id; KFd +7C9  
fileAccessI = new FileAccessI(sName,nStartPos);//定位 7Ed0BJTa  
} 112WryS  
qjP~F  

n[iwi   
public void run() ^?`fN'!p  
{ Swhz\/u9  
while(nStartPos < nEndPos && !bStop) \5r^D|Rp}  
{ 9:USxFM  
J[ Gpd  
@|a
nu&Hm  
try{ K6IT$
$g  
URL url = new URL(sURL); o+E~iCu5  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); '^m.vS
!/  
httpConnection.setRequestProperty("User-Agent","NetFox"); 3\XNOJH  
String sProperty = "bytes="+nStartPos+"-"; cmG27\cRO  
httpConnection.setRequestProperty("RANGE",sProperty); ;{sZDjev>  
Utility.log(sProperty); d&FXndC4F  
BV~J*e  
&)1.z7T  
InputStream input = httpConnection.getInputStream(); STW?0B'Jr  
//logResponseHead(httpConnection); )[Tm[o?Y.  
rv*{[K  
L3, /7  
byte[] b = new byte[1024]; c| ^I}  
int nRead; F] c\Qt  
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) '@t$3 hk  
{ T7,]^ 1  
nStartPos += fileAccessI.write(b,0,nRead); `MOw\Z)..  
//if(nThreadID == 1)
M*zpl}  
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); @sLN  
} +#FqC/`l  
7 m{lOR  
!cyrt<  
Utility.log("Thread " + nThreadID + " is over!"); '? 5
-  
bDownOver = true; ^5sA*%T4  
//nPos = fileAccessI.write (b,0,nRead); PXMd=,}  
} w.?4}'DK  
catch(Exception e){e.printStackTrace ();} vhfjZ  
} %;'~TtW5  
} 4E^ ?}_$  
H0afu)$,  
~XTC:6ts  
//打印回应的头信息 ~S8:xG+s  
public void logResponseHead(HttpURLConnection con) Qo#]Lo> \g  
{ V+E8{|dYL  
for(int i=1;;i++) 8Sr'  
{ 
,UY1.tR(  
String header=con.getHeaderFieldKey(i); .Fo#Dmq3  
if(header!=null) "JB4Uaa  
//responseHeaders.put(header,httpConnection.getHeaderField(header)); TJ"-cWpO1  
Utility.log(header+" : "+con.getHeaderField(header)); xnZnbgO+  
else )zr*Ecz  
break; BiYxI{VFD  
} b)d;eS  
} BDI|z/~&  
[H}> 2Q  
NU=ru/  
public void splitterStop() HOP*QX8C%  
{ g<j)   
bStop = true; Z =+Z96  
} xe!bfzU  
8fXiadP#  
!Y~UO)u2  
} Y2r}W3F=  
Q@W/~~N  
cRT'?w`}  
/* -5<[oBL;  
**FileAccess.java |R}=HsYey  
*//文件访问(定位，写) >w S'z]T9  
package NetFox; k>($[;k|b  
import java.io.*; (P|[<Sd  
G4cgY|71  
V`I4"}M1  
public class FileAccessI implements Serializable{ _,J+b R+b  
|MwV4^  
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 I1<WHq  
RandomAccessFile oSavedFile; 6'#5Dqw"r  
long nPos; TjUwe@&Rw  
<s9{o uZ  
N:lfKI  
public FileAccessI() throws IOException {kpF etXt?  
{ z?o8h N\  
this("",0); X8)k'h  
} 4IeCb?  
l 
f>/  
k =!
Q  
public FileAccessI(String sName,long nPos) throws IOException {MgRi7  
{ xuioU  
oSavedFile = new RandomAccessFile(sName,"rw"); ;U* /\+*h  
this.nPos = nPos; /v 8"i^;}  
oSavedFile.seek(nPos); p'R<yB)V  
} jWrU'X  
X)b$CG  
WNyW1?"  
public synchronized int write(byte[] b,int nStart,int nLen) h4;kjr}h}  
{ jK w 96  
int n = -1; `_\KN_-%Vu  
try{ I C  
oSavedFile.write(b,nStart,nLen); [HILK`@@  
n = nLen; FIq'W:q:  
} *#=Ijr~  
catch(IOException e) nR_Zrm  
{ QG5WsuT  
e.printStackTrace (); <*(Z}p  
} Kip&YB%rk  
luoQ#1F?sl  
Aw#<:6-  
return n; (]
]hSkE  
} !xsfhLZK  
*vb"mB  
vIV|y>;g  
} ,Z{\YAh1  
8b/$Qp4d  
[IYVrT&C'  
/* AQ,lLn+  
**SiteInfoBean.java a-NTA  
*/ }Ng P`m  
package NetFox; Rc1j^S;>  
eCGr_@1  
N>I6f  
public class SiteInfoBean { :HY$x  
JS/'0.  
fL*7u\m:  
private String sSiteURL; //Site's URL N5?bflY  
private String sFilePath; //Saved File's Path xw#CwMbbi  
private String sFileName; //Saved File's Name 1:-'euA"  
private int nSplitter; //Count of Splited Downloading File yv,FzF}7  
\=%lH=yS  
z!}E2j_9P  
public SiteInfoBean() 6 U.Jaai:  
{//nSplitter的缺省值为5 a4*v'Xc5  
//default value of nSplitter is 5 Q"&Mr+  
this("","","",5); V*?c
MJ_G  
} F^%w%E\  
8V:;HY#  
6W i n!4  
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) o~LJ+m6-)  
{ ]_s3<&R  
sSiteURL= sURL; ]1 f^ SxSI  
sFilePath = sPath; Dz}i-tw+  
sFileName = sName; [ws _ g,/  
this.nSplitter = nSpiltter; &N}"4  
e9LX0=  
~` tuPk~l  
} 0Ui.nz j  
$TUYxf0q  
x3O%W?5  
public String getSSiteURL() CNNqS^ct  
{ [> HKRVy  
return sSiteURL; [mtp-4*  
} ob7'''i  
VX)8pV$  
65LtCQ}  
public void setSSiteURL(String value) *;A ;)'  
{ D \ rns+  
sSiteURL = value; [:X@|,1V!L  
} qTuR[(  
Mq> 4!  
b31$i 5{  
public String getSFilePath() w.m8SvS&b  
{ BE?]P?r?  
return sFilePath; pCKP{c=6Q  
} /2K"Mpf8  
K6v~!iiK$  
I5"wa:Z  
public void setSFilePath(String value) ^+(5[z  
{ $?GggP d  
sFilePath = value; SEgw!2H  
} h#0n2o#  
;$D,w  
iK}p#"si  
public String getSFileName() KsULQJ#,  
{ C*Q7@+&  
return sFileName; :C5w5 Vnj  
} !Rv ;~f/2  
5IU!BQU  
//@6w;P  
public void setSFileName(String value) R_EU|a
  
{ j^jC|  
sFileName = value; S`-I-VS=L  
} lelmX  
fJ}e  
i c{I  
public int getNSplitter() :w8{BIUN)  
{ S m(*<H  
return nSplitter; m H:Un{,  
} T!jh`;D+  
 u$?!  
WuK<?1meN  
public void setNSplitter(int nCount) V!:!c]8F  
{ e:G~P u`  
nSplitter = nCount; >.wZEQ6QK  
} 3Zp<#  
} <#0i*PM_  
+^7cS6"L  
!oz{XWE  
/* Dw i-iA_q  
**Utility.java 'aNkU  
*/ Pt"K+]Ym  
package NetFox; h8V*$  
,:Px(=d4  
Yn?beu'  
public class Utility { 1Ek3^TOv7  
u7e$Mq  
l,|Llb  
public Utility() CPZ{  
{ SK}jhm"y  
Luao?;|U  
:hICe+2ca  
} [Qs`@u<%  
-VohU-6 |  
//线程睡眠 YdD; Qx#O  
public static void sleep(int nSecond) $:u*)&"t|  
{ YKe&Ph.  
try{
-
mJs0E*g  
Thread.sleep(nSecond); QFnuu-82"  
} ld(60?z>FH  
catch(Exception e) i9 aR#  
{ !Yc:yF  
e.printStackTrace (); ^fF#Ej1  
} 
JpXv+V  
} 9d1km~  
c =m#MMc)  
//日志 NVzo)C8kb  
public static void log(String sMsg) :'DX M{  
{ IJf%OA>v  
System.err.println(sMsg); &r[f ;|o  
} \]>821r  
CDJ@Tdp  
!$Uo$?gC  
public static void log(int sMsg) ij]UAJ}t  
{ Dbn~~P  
System.err.println(sMsg); e"
866vc,  
} 1(;{w+nM  
}  r(^00hvH  

|?KYY0  
D:k< , {  
/* K qJE?caw  
**TestMethod.java kw59`z Es  
*/ ,X/j6\VBO  
package NetFox; _4oAk @A  
^mC~<pP(  
:uYZ1O  
public class TestMethod { .5 E)dU  
ue8 @=}  
)Q1aAS3  
public TestMethod() *o1US  
{ ///xx/weblogic60b2_win.exe >|S@twy  
try{ 3nB
Z+n4
z  
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); /J^dzvH  
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); 23CvfP  
SiteFileFetch fileFetch = new SiteFileFetch(bean); !WXV1S  
fileFetch.start(); ,OlS>>,  
} |2'WSAWG  
catch(Exception e){e.printStackTrace ();} .7.1JT#@A7  
w!UF^~  
fDYTupKXH  
} `N[@lV\xp!  
R\cx-h*  
TJYhgna  
public static void main(String[] args) OK4r)  
{ ,LZA\XC  
new TestMethod(); v RD/67  
} 38sLyoG=i  
} =b66H]h?  
点击下载更多相关资料