http断点续传简单实现（java)

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0 发表于: 2006-05-10

/*
**SiteFileFetch.java
*/
package NetFox;
import java.io.*;
import java.net.*;

public class SiteFileFetch extends Thread {

SiteInfoBean siteInfoBean = null; //文件信息Bean
long[] nStartPos; //开始位置
long[] nEndPos; //结束位置
FileSplitterFetch[] fileSplitterFetch; //子线程对象
long nFileLength; //文件长度
boolean bFirst = true; //是否第一次取文件
boolean bStop = false; //停止标志
File tmpFile; //文件下载的临时信息
DataOutputStream output; //输出到文件的输出流

//负责整个文件的抓取，控制内部线程（FileSplitterFetch类）
public SiteFileFetch(SiteInfoBean bean) throws IOException
{
siteInfoBean = bean;
//tmpFile = File.createTempFile ("zhong","1111",new File(bean.getSFilePath()));
tmpFile = new File(bean.getSFilePath()+File.separator + bean.getSFileName()+".info");
if(tmpFile.exists ())
{
bFirst = false;
read_nPos();
}
else
{
nStartPos = new long[bean.getNSplitter()];
nEndPos = new long[bean.getNSplitter()];
}

}

public void run()
{
//获得文件长度
//分割文件
//实例FileSplitterFetch
//启动FileSplitterFetch线程
//等待子线程返回
try{
if(bFirst)
{
nFileLength = getFileSize();
if(nFileLength == -1)
{
System.err.println("File Length is not known!");
}
else if(nFileLength == -2)
{
System.err.println("File is not access!");
}
else
{
for(int i=0;i<nStartPos.length;i++)
{
nStartPos = (long)(i*(nFileLength/nStartPos.length)); 75^)Ni
} UeK,q>i
for(int i=0;i<nEndPos.length-1;i++) 5Tcl<Y6l
{ [TpA26#TTO
nEndPos = nStartPos[i+1]; tDuUAI54
} CBz(hCaI
nEndPos[nEndPos.length-1] = nFileLength; f6dE\
} cN[q)ts
} CguU+8]
zO7lsx2=
Rd;~'gbG
//启动子线程 %Hl:nT2M
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; 3=G5(0
for(int i=0;i<nStartPos.length;i++) y~#R:&d"
{ 7#~m:K@
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), (<g;-pZH%
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), Np5/lPb1
nStartPos,nEndPos,i); =%#$HQ=
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); /4f 5s#hR
fileSplitterFetch.start(); pRDON)$
} leX7(Y;!a7
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), C4X{Ps\
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); }.Na{]<gh
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", C7c|\T
nEndPos = " + nFileLength); oto wvm
// fileSplitterFetch[nPos.length-1].start(); zwniS6R1
k8t Na@H
0W<nE[U
//等待子线程结束 hD9'`SQ
//int count = 0; sWpRX2{5,
//是否结束while循环 nw]e_sm
boolean breakWhile = false; \CEnOq
6LF^[b/u
#u]_7/(</`
while(!bStop) 2Xq!'NrS
{ x:&L?eOT
write_nPos(); tp,mw24
Utility.sleep(500); ngH~4HyT
breakWhile = true; c?3F9w#
ck4T#g;=
9DP75 ti
for(int i=0;i<nStartPos.length;i++) wYS KtG~/S
{ "YdDaj</
if(!fileSplitterFetch.bDownOver) |WwFE|<
{ dBD4ogo1
breakWhile = false; \qK}(xq[
break; +%cr?g
} 8d*<Aki?;
} KWuj_.;
if(breakWhile) xa%ktn
break; {bq-: CZe
j}x O34
=ty@xHr
//count++; M$5%QM}
//if(count>4) 0z<]\a4
// siteStop(); 5M.n'*
} 4|o{_g[
aR(Z~z;C
q0KXuMK
System.err.println("文件下载结束！"); J9KLO=
} bZ@53
catch(Exception e){e.printStackTrace ();} Xy(SzJ%
} %n`iA7j$W
vM>`CZ
/j5- "<;.
//获得文件长度 NcY0pAR*
public long getFileSize() k;Ny%%5
{ 3~1lVU:
int nFileLength = -1; (P52KD[A[
try{ fylA0{
URL url = new URL(siteInfoBean.getSSiteURL()); c%,6L<[
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 3x;y}:wQa
httpConnection.setRequestProperty("User-Agent","NetFox"); C9;X6
$\J9F=<a
{p_vR/yN
int responseCode=httpConnection.getResponseCode(); #o |&MV_j
if(responseCode>=400) r1H['{$
{ CR8r|+(8
processErrorCode(responseCode); \oZUG
return -2; //-2 represent access is error QT&Ws+@ s{
} ah$7 Oudj
1#X=&N
:@807OYzy
String sHeader; kG7,1teMk
$(mdz)Cfy
=&g}Y
for(int i=1;;i++) aD3F!Sn
{ v]Q_
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); (,9cCnvmYU
//Utility.log(in.readLine()); k)GuMw
sHeader=httpConnection.getHeaderFieldKey(i); \fFy$
if(sHeader!=null) 1?#p !;&
{ z?> y
if(sHeader.equals("Content-Length")) M,!no
{ vz_g2.7l\
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); W%<]_u[-}
break; 0-; P&m!!
} ~ z&A
} E#F9<=mA)
else H5MAN,`
break; 58ZiCvqv
} ?)QBJ9F
} W[Ew6)1T
catch(IOException e){e.printStackTrace ();} AT'$VCYC(
catch(Exception e){e.printStackTrace ();} +jZg%$Q!#
N#!1@!2BN
7Mg7B
Utility.log(nFileLength); KGLhl;a
GyM%vGl 3
v.&*z48
return nFileLength; }eRG$)'
} kvVz-PJy
rQ@o
cb&In<q
//保存下载信息（文件指针位置） teNQUIe-
private void write_nPos() bRe*(
{ Saq>o.
try{ v?"ee&Y6
output = new DataOutputStream(new FileOutputStream(tmpFile)); EKJ4_kkjM
output.writeInt(nStartPos.length); E/-Kd!|"
for(int i=0;i<nStartPos.length;i++) W%ZU& YBc
{ l*MUDT@M8\
// output.writeLong(nPos); v?=VZ~`O(
output.writeLong(fileSplitterFetch.nStartPos); P\0%nyOG(%
output.writeLong(fileSplitterFetch.nEndPos); *H<g9<Dn
} QgM_SY|Rj
output.close(); ~g6[ [
} c'TLD!^hB
catch(IOException e){e.printStackTrace ();} =WRU<`\
catch(Exception e){e.printStackTrace ();} R6o<p<fTh
} 5 9HaTq
x9 L\"
. pEeR
//读取保存的下载信息（文件指针位置） g;Q^_4@
private void read_nPos() ]p.f*]
{ NGZ>:
try{ "/h"Xg>q
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); NJ!#0[@C
int nCount = input.readInt(); M\4;d #
nStartPos = new long[nCount]; c)YGwkY,,
nEndPos = new long[nCount]; #;\;F PuZ
for(int i=0;i<nStartPos.length;i++) `%I{l
{ ##ea-"m8
nStartPos = input.readLong(); #/=yz<B
nEndPos = input.readLong(); 3t6'5{
} yk6UuI^/
input.close(); #{cpG2Rs
} yj9gN}+
catch(IOException e){e.printStackTrace ();} Rk0rHC6[
catch(Exception e){e.printStackTrace ();} Y[]t_o)
} {NqGWkGt*b
w:@M|O4`
<:t\P.
private void processErrorCode(int nErrorCode) +ANIm^@
{ S.>9tV2Ca
System.err.println("Error Code : " + nErrorCode); +-137!x\q
} #$)rwm.jW?
H pfI
=W^L8!BE'
//停止文件下载 Z6ex<[`I
public void siteStop() ?kefRev<#h
{ R6.#gb8^oS
bStop = true; Q'M Ez
for(int i=0;i<nStartPos.length;i++) 3!UP>,!
fileSplitterFetch.splitterStop(); 3`q`W9
oob0^}^
j2n@8sCSO
} ]}c=U@D,9
} . M$D
//负责部分文件的抓取 a{.n(M
**FileSplitterFetch.java pD/S\E0@t
*/ 9}_f\Bs
package NetFox; DYl{{L8@
`t2! M\)
CU&,Kq@
import java.io.*; 9xp ;$14
import java.net.*; |?W
+:Zi(SuS]
Ik)Q0_<a
public class FileSplitterFetch extends Thread { "&|2IA
] 6B!eB !
|{"7/~*[
String sURL; //File URL !A0bbJ
long nStartPos; //File Snippet Start Position rnaDo\5
long nEndPos; //File Snippet End Position 9?6$2I
int nThreadID; //Thread's ID .r"?w
boolean bDownOver = false; //Downing is over 9>P(eN
boolean bStop = false; //Stop identical [! BH3J!
FileAccessI fileAccessI = null; //File Access interface IGQ8-#=
0~+k
_xsYcw~)
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException vBXr[XoC
{ H:Le^WS
this.sURL = sURL; ,' B=eY,
this.nStartPos = nStart; gC 4#!P
this.nEndPos = nEnd; (k45k/PAP
nThreadID = id; =,]M$M
fileAccessI = new FileAccessI(sName,nStartPos);//定位 2F{IDcJI\
} .[A S
=0Sa
~`.%n7
public void run() |XZf:}q5:
{ u9(AT>HxT
while(nStartPos < nEndPos && !bStop) 9$i`B>C~
{ ;& +75n
?^p8]Va%
D._r@~o
try{ ks4 ,2f,2
URL url = new URL(sURL); n4,J#h/
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); %9M49s
httpConnection.setRequestProperty("User-Agent","NetFox"); x$I>e
String sProperty = "bytes="+nStartPos+"-"; MG>;|*$%
httpConnection.setRequestProperty("RANGE",sProperty); ,//=yW
Utility.log(sProperty); =G6@:h=
#n r1- sf|
M$9h)3(B
InputStream input = httpConnection.getInputStream(); y0]O 6.{
//logResponseHead(httpConnection); sqRuqUj+
G=e[TR)i
y 6<tV.
byte[] b = new byte[1024]; qMOD TM~+
int nRead; Hy'&x?F6
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) _L>n!"E/
{ o~p^`5#
nStartPos += fileAccessI.write(b,0,nRead); (ShJ!
//if(nThreadID == 1) 4LLCb7/5lP
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); pDQ,v"
} ^<-SW]x
;{RQ+ZX'[
j*}xe'#
Utility.log("Thread " + nThreadID + " is over!"); M-hnBt
bDownOver = true; r9[J3t*({~
//nPos = fileAccessI.write (b,0,nRead); g;T`~
} pz+#1=b]
catch(Exception e){e.printStackTrace ();} ?*=Jq
} tTal<4
} uDR(^T{g#
10(N|2'q
uQCS%|8C
//打印回应的头信息 ]LjW,b"
public void logResponseHead(HttpURLConnection con) Re_.<_$
{ C4,W[L]4"
for(int i=1;;i++) =9-c*bL
{ vr$[
String header=con.getHeaderFieldKey(i); '"Gi&:*nQ<
if(header!=null) ko$R%W&T
//responseHeaders.put(header,httpConnection.getHeaderField(header)); =8-e1R/
Utility.log(header+" : "+con.getHeaderField(header)); -L@=j
else zuw6YY8kQ
break; :O2N'vl47A
} XT)@)c7j
} `KN{0<Ne
%BJ V$tO
"PPwJ/L(
public void splitterStop() #%~wuCn<K
{ u}$3.]-.?T
bStop = true; kmwFw>#
} ~Q5HM
Wp $\>
*&s_u)b
} FsjblB3?E
&>SE9w/?o
r.[kD"l
/* }tN"C 3)@
**FileAccess.java Flsf5 Tr0
*//文件访问(定位，写) HXX"B,N
package NetFox; TD<.:ul]
import java.io.*; 3 }XS|Y
'tekne
3~ylBJJ
public class FileAccessI implements Serializable{ occ}|u
Pg7/g=Va
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 [LE_lATjU
RandomAccessFile oSavedFile; 3$_wAt4w
long nPos; Ad(j&P
idHBz*3~ps
YRFM1?*
public FileAccessI() throws IOException 6B=J*8 Hs
{ h8Gp>b
this("",0); w5p+Yx=q
} /n_N`VJ7H
HjrCX>v
lq74Fz&(
public FileAccessI(String sName,long nPos) throws IOException &12.|
{ 92EvCtf
oSavedFile = new RandomAccessFile(sName,"rw"); R"jX9~3Ln
this.nPos = nPos; $4m{g"xL
oSavedFile.seek(nPos); z?7pn}-
} Lq:Z='Kc
]`%cTdpLj
o4xZaF4+
public synchronized int write(byte[] b,int nStart,int nLen) ral0@\T
{ >Gkkr{s9
int n = -1; =Z2sQQVS
try{ tq{ aa
oSavedFile.write(b,nStart,nLen); rc"yEI-``"
n = nLen; qSON3Iid
} ^vUdf.n9
catch(IOException e) d:3G4g
{ WK-WA$7\
e.printStackTrace (); 6H@=O1W
} ]O^!P,l)"
rxO|k0x^C
_("{fJ,A
return n; l&zd7BM9(
} a4?:suX$
P:=3;d{v
,{$:Q}`
} 7P=j2;7 v
tcfUhSz,I
RDZl@ps8
/* koFY7;_<?
**SiteInfoBean.java k@^)>J^
*/ R4{2+q=0
package NetFox; )]'?yS"
E1=]m
Lf3:' n
public class SiteInfoBean { cJ&%XN
o@}Jd0D4
Wcbb3N$+
private String sSiteURL; //Site's URL +PjH2
private String sFilePath; //Saved File's Path vV8}>
private String sFileName; //Saved File's Name 7^=O^!sa
private int nSplitter; //Count of Splited Downloading File 0EOpK%{
M%Ov6u<I8
tT'+3
public SiteInfoBean() aB.`'d)V
{//nSplitter的缺省值为5 7cH[}v`pn
//default value of nSplitter is 5 xI$B",?(
this("","","",5); 'F1NBL
} A#*0mJ8IK
mV6\gR[h
ht` !@B
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) \xwE4K
{ +c?1\{M
sSiteURL= sURL; XDU&Z2A
sFilePath = sPath; {2A/@$?
sFileName = sName; z>~Hc8*]3
this.nSplitter = nSpiltter; ?Yxk1Y4ig)
jT%k{"+>+?
i!9yN:m0
} K[O'@v
^8-CUH\
s-[_%
public String getSSiteURL() xDm^f^}>
{ =JY9K0S~
return sSiteURL; wj/OYnMw
} }sZme3*J[
y]yp8Bs+
x pT85D
public void setSSiteURL(String value) #)z_TM07P
{ pPUKx=d
sSiteURL = value; D3N\$D
} 6Dwj^e0
_Uc le
Srg`Tt]
public String getSFilePath() v[\' M
{ wS9EC}s:Q
return sFilePath; b$[O^p9x
} BNL Q]
{fmSmD
q,A;d^g
public void setSFilePath(String value) A46Xei:Ow
{ f 0D9Mp
sFilePath = value; _ 7X0
} k%Jv%m}aB
Mt"j< ]EW
C;QIp6"1
public String getSFileName() 0x*L"HD
{ _gxI=EYi
return sFileName; _Gvn1"l
} |5^tp
e4ym6q<6!
kO>F, M
public void setSFileName(String value) MIGcV9hf
{ (< gk<e*
sFileName = value; gZ8n[zxf6
} hi^@969
~RgO9p(dY
UsP1bh4
public int getNSplitter() E|P
{ !lpKZG
return nSplitter; !36jtKdM
} 4Hc+F(
q$7SJ.pF
R9%Um6
public void setNSplitter(int nCount) lu2"?y[2
{ <?znk8|
nSplitter = nCount; 6qp2C]9=
} VPBlU
} ZUPlMHc
pCb3^# &o
/Sy:/BQ
/* WrP4*6;"
**Utility.java KG=h!]Meq
*/ *uoc;6
package NetFox; OiAP%7i9
OFH!z{*
[Vzp D 4
public class Utility { FtHR.S=u
IY jt*p5
rXgU*3RG
public Utility() D; i%J
{ T$)N2]FE
i^`]TOP
^FJ.C|l(
} y(!J8(yA
`IN/1=]5
//线程睡眠 AM?62
public static void sleep(int nSecond) `0'Bg2'
{ 2vbm=~)$F
try{ pH!e<m
Thread.sleep(nSecond); MOp06
} fg}&=r
catch(Exception e) C 0@tMB7
{ MhT.Zg\
e.printStackTrace (); ti%uyXfja
} (^,4{;YQ5
} u6tD5Y
!5FZxmUup
//日志 y{{7)G
public static void log(String sMsg) Tp-<!^o4
{ ,-({m'
System.err.println(sMsg); :70n%3a
} bUJ5jkZ)
5^:N]Mp"
fZ8at
public static void log(int sMsg) z;fi
{ /8](M5X]f
System.err.println(sMsg); 5BWO7F0v"
} vuP.V#
} \l$gcFXb
x.J% c[Q8
x|3f$ =b
/* y<#?z 8P
**TestMethod.java #RIo63
*/ n\CQ-*;l
package NetFox; 6<E4?<O%
2pu8')'P
g3*" ^C2=
public class TestMethod { Y5rR
H#zsk*=QD
Dl/Jlsd@
public TestMethod() 7=Vs1TVc
{ ///xx/weblogic60b2_win.exe ;}/@ar7s3
try{ KNH.4A ,
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); {Ftz4y)6
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); 4^|;a0Qy]
SiteFileFetch fileFetch = new SiteFileFetch(bean); WcE{1&PXx
fileFetch.start(); L!fiW`>0G
} *p&c}2'
catch(Exception e){e.printStackTrace ();} 8Df(|>mK
TttD}`\.
+aa( YGL
} {Vg8pt
gtizgUS7
MGoYL\
public static void main(String[] args) <|,0%bq)|
{ 8 oK;Tzh
new TestMethod(); P8Nzz(JF
} XnBpL6"T`
} Ry5/O?QL
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