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)); H^S<bZ
} :P2!& W
for(int i=0;i<nEndPos.length-1;i++) <^5$))r
{ !xR9I0V5
nEndPos = nStartPos[i+1]; p\;8?x
} j[dZ*Jr_
nEndPos[nEndPos.length-1] = nFileLength; F::Ki4{jJ
} 3>L5TYa
} }MMKOr(
\ Xh C
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//启动子线程 "k@[7 7
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; Pi?G:IF
for(int i=0;i<nStartPos.length;i++) 965x_ %
{ svEe@Kt`
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), ?32~%?m
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), Myg;2.
nStartPos,nEndPos,i); *`w>\},su
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); m`8{arz2
fileSplitterFetch.start(); +l)t5Mg\
} JS m7-p|E
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), }UGSE2^1
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); )Z/w|5<
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", P nE7}
nEndPos = " + nFileLength); T>(X`(
// fileSplitterFetch[nPos.length-1].start(); v8 =#1YB;
vO9=CCxvq
Y0lLO0'
//等待子线程结束 4V,p\$;
//int count = 0; hwe6@T.#
//是否结束while循环 $X Uck[
boolean breakWhile = false; V1d#7rP
?b(wZ-/
s Y1@~v
while(!bStop) s=jH1^
{ MmvJ)|&t
write_nPos(); <h#W*a
Utility.sleep(500); )ej1)RU"
breakWhile = true; H"w;~;h
;Qt/(/
Oj%5FUP~[%
for(int i=0;i<nStartPos.length;i++) 'Y ,2CN
{ x5PM]~"p
if(!fileSplitterFetch.bDownOver) s92ol0`
{ ^}vf
breakWhile = false; @UdF6:T
break; q+8de_"]
} #Pd__NV"\
} *74/I>i
if(breakWhile) jf;n*
break; b#6mUl2
;/4x.t#b
F`eE*&
//count++; pO)EYla9
//if(count>4) i;]0>g4
// siteStop(); uc"%uc'
} .7Yox1,
5({_2meJ:
X8*~Cf73u
System.err.println("文件下载结束！"); .6rbn8h
} W-r^ME
catch(Exception e){e.printStackTrace ();} ^vSSG5 :
} pV8tn!
5K?/-0yG
q!U$\Q&
//获得文件长度 K>~YO~~
public long getFileSize() kUGFg{"
{ GL9'dL|
int nFileLength = -1; R%2.N!8v
try{ 7>MG8pf3a
URL url = new URL(siteInfoBean.getSSiteURL()); Z6Mjc/
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); W)f=\.7
httpConnection.setRequestProperty("User-Agent","NetFox"); NM:$Q<n
j7w9H/XF}
n;=FD;}j+
int responseCode=httpConnection.getResponseCode(); {y5 L
if(responseCode>=400) <"p-0=IgJ
{ Zz:%KUl3
processErrorCode(responseCode); FhBV.,bU,m
return -2; //-2 represent access is error 5/U{b5
} [8Z#HjhQ
;m.6 ~A
^K J#dT
String sHeader; 9:xs)t- _
l+y;>21sTu
sb_/FE5e
for(int i=1;;i++) ) 5Ij
{ $E;Tj|W
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); 6Ktq7'Z@
//Utility.log(in.readLine()); +{;wOQ.
sHeader=httpConnection.getHeaderFieldKey(i); 1D[>oK\
if(sHeader!=null) &CXk=Wj
{ kQ&Q_FSO
if(sHeader.equals("Content-Length")) Z 369<
{ ,S(Z\[x0
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); Hq>hnCT
break; c]U+6JH
} Jh%SenP_oP
} 9o?\*{'KT
else 3 .j/D^
break; RRQv<x
} Bnwq!i!M
} JP( tf+
catch(IOException e){e.printStackTrace ();} ~bzac2Rp
catch(Exception e){e.printStackTrace ();} *m>[\)
RiQg]3oY
Jo;&~/V
Utility.log(nFileLength); >tMI%r
<9xr?i=
1Lje.%(E.
return nFileLength; dSTyx#o
} wRK27=\z
m&q0 _nay
|XNw&X1VF
//保存下载信息（文件指针位置） }#&[[}@th
private void write_nPos() E&t8nlTx
{ :,$"Gk
try{ E^{!B]/oP
output = new DataOutputStream(new FileOutputStream(tmpFile)); 6pC1C.
output.writeInt(nStartPos.length); Vz-q7*o$S
for(int i=0;i<nStartPos.length;i++) csJ)Pt?d
{ PC255
// output.writeLong(nPos); c,)]!{c
output.writeLong(fileSplitterFetch.nStartPos); s7:_!Nd@8
output.writeLong(fileSplitterFetch.nEndPos); y>h9:q|
} pNQ7uy
output.close(); /D|q-`*K
} s]A8C^;c
catch(IOException e){e.printStackTrace ();} ;[P>
catch(Exception e){e.printStackTrace ();} 5f0g7w =-
} xbcmvJrG
(5+g:mSfr
hHDLrr
//读取保存的下载信息（文件指针位置） bJ6C7-w:wa
private void read_nPos() >6WZSw/Hq
{ ?D9iCP~~
try{ >PQ?|Uk
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); &KI|qtQ;
int nCount = input.readInt(); p0CPeH
nStartPos = new long[nCount]; a[rb-Z
nEndPos = new long[nCount]; c8Q2H
for(int i=0;i<nStartPos.length;i++) ]b1>bv%
{ 1!U:M8T|
nStartPos = input.readLong(); jyyig%
nEndPos = input.readLong(); b9T6JS j
} EvY^]M_U
input.close(); `0_ Y| 4KB
} >mMfZvxl%
catch(IOException e){e.printStackTrace ();} Vom,^`}
catch(Exception e){e.printStackTrace ();} l(F\5Ys
} # &5.
\3K7)o^
GA[bo)"
private void processErrorCode(int nErrorCode) C+`V?rp=s
{ H{9P=l
System.err.println("Error Code : " + nErrorCode); [wQJVYv
} Z1$U[Tsd
8D?$@!-
/yx)_x{
//停止文件下载 &e*@:5Z:k
public void siteStop() Hdd3n6*
{ Mty[)+se
bStop = true; fTK84v"7_
for(int i=0;i<nStartPos.length;i++) 4eSFpy1
fileSplitterFetch.splitterStop(); DaGny0|BB
&{qKoI]
>RJ&b
} rADzJ#CU\
} KC(z TY
//负责部分文件的抓取 B *6ncj
**FileSplitterFetch.java LIz'hfS!
*/ Kf$(7FT'`
package NetFox; L5|g\Y`
r>*+d|c4
HmU6:8V *Z
import java.io.*; #D{Eq8dp
import java.net.*; 9Nv?j=*$
X$P(8'[9A
[[N${C
public class FileSplitterFetch extends Thread { %" l;
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lt2MB#
String sURL; //File URL xA-?pLt"G
long nStartPos; //File Snippet Start Position i!RYrae
long nEndPos; //File Snippet End Position GGhk`z
int nThreadID; //Thread's ID S^EAE]
boolean bDownOver = false; //Downing is over ` ` Yk
boolean bStop = false; //Stop identical {%y|A{}c
FileAccessI fileAccessI = null; //File Access interface $[7/~I>m
.O#7X
w?N>3`Jnf
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException ,PJC FQMR
{ )4:]gx#cr
this.sURL = sURL; <1*\ ~CX
this.nStartPos = nStart; R4k+.hR
this.nEndPos = nEnd; [)0^*A2
nThreadID = id; Vwjic2lGI
fileAccessI = new FileAccessI(sName,nStartPos);//定位 KPjAk
} /PR4ILed
oj'YDQ^uj
VTyj<6Y
public void run() 31e O2|7
{ ^~bdAO81
while(nStartPos < nEndPos && !bStop) A+4Kj~`!
{ "f~OC<GdYs
cg9}T[A
z> DQ
try{ iAXGf V
URL url = new URL(sURL); lHTr7uF(
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); zh\"sxL
httpConnection.setRequestProperty("User-Agent","NetFox"); 9v3n4=gc
String sProperty = "bytes="+nStartPos+"-"; t6\--lk_
httpConnection.setRequestProperty("RANGE",sProperty); #mK?:O\-1
Utility.log(sProperty); Gui[/iY,F
uf (_<~
hJk:&!M=T
InputStream input = httpConnection.getInputStream(); q0vZR"y
//logResponseHead(httpConnection); X*5N&AJ
UVgSO|Tg
\l 8_aj
byte[] b = new byte[1024]; `Gl[e4U
int nRead; ?gvu E1
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) &2q<#b
{ eU e, P
nStartPos += fileAccessI.write(b,0,nRead); lq,]E/<&
//if(nThreadID == 1) kDM?`(r
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); U&a(WQV9&
} ~.0'v [N
'^[+]
w8J8III\~
Utility.log("Thread " + nThreadID + " is over!"); IJDbm}:/e
bDownOver = true; +KNd%AJ
//nPos = fileAccessI.write (b,0,nRead); EdSUBoWF}
} zM<L_l&
catch(Exception e){e.printStackTrace ();} +qT+iHa|n
} 8$ #z>
} @'?gan#(
b^ [ z'
mh SknyqT
//打印回应的头信息 1~LfR
public void logResponseHead(HttpURLConnection con) hk S:_e=
{ UTN[!0[
for(int i=1;;i++) .P?n<n#
{ 2Yd@V}
String header=con.getHeaderFieldKey(i); [cl+AV "
if(header!=null) 2cRru]VZ5
//responseHeaders.put(header,httpConnection.getHeaderField(header)); IXm[c@5l
Utility.log(header+" : "+con.getHeaderField(header)); $% gz,{
else .n)R@&9
break; ue'dI
} I'p+9H$
} }4h0{H
:2C <;o
>Q[ Z{
public void splitterStop() SB.=x
{ }Ya! [tX
bStop = true; 0) F\aJ4Y
} Y"yrc0'&T
%f1IV(3Qc
Hr!$mf)h
} -Wh 2hWg+
{9x>@p/
;fN^MW@&[
/* T0)bnjm
**FileAccess.java )EKWsGNe/
*//文件访问(定位，写) .jtv Hr}U
package NetFox; ]+B.=mO_
import java.io.*; ^W@%(,xb
(~E-=+R[$&
&rPAW V'v
public class FileAccessI implements Serializable{ 6PS[OB{3
SBDGms
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 FH$q,BI!R
RandomAccessFile oSavedFile; _G'A]O/BZD
long nPos; Q6e7Z-8
Cg`lQYU
7l~^KsX
public FileAccessI() throws IOException *,*O.#<6
{ ~kSOYvK$'
this("",0); t*A[v
} UX<-jY#'V
NJ-Ji> w
J2! Q09 }5
public FileAccessI(String sName,long nPos) throws IOException ^yq}>_
{ vNl)ltzJF
oSavedFile = new RandomAccessFile(sName,"rw"); a l6y=;\jZ
this.nPos = nPos; .cw)Y#;IG
oSavedFile.seek(nPos); hN]l $Ct
} 5;^1Ab0
TJZ~Rpq
v-q-CI?B#
public synchronized int write(byte[] b,int nStart,int nLen) z9g6%RbwX
{ fiD,HGx i
int n = -1; B$x@I\(M
try{ i'"#{4I
oSavedFile.write(b,nStart,nLen); ZZTf/s*
n = nLen; ]FIIs58IM
} 1EC;t1.7
catch(IOException e) \0_jmX]p
{ ;Oqf{em];
e.printStackTrace (); ']+!i a
} CmBgay
>P\eHR,{-
c_M[>#`
return n; jWi~Q o+
} gTOx|bx
: xggo
"e8EA!Ipte
} :D-D+x
oSkQ/5hg.
bR~(Ry`
/* _;Xlw{FN^
**SiteInfoBean.java )z18:C3
*/ u~Po5W/i
package NetFox; gW--[
>wt.)c?5
kD%MFT4
public class SiteInfoBean { Jvsy 6R
\=im{(0h
cRD;a?0/6s
private String sSiteURL; //Site's URL SG|AJ9
private String sFilePath; //Saved File's Path \ERxr
private String sFileName; //Saved File's Name F8{gJaP x
private int nSplitter; //Count of Splited Downloading File ]sL.+.P
Y;huTZ
t!6uz
public SiteInfoBean() Ka-o$o[^u`
{//nSplitter的缺省值为5 JehanF[
//default value of nSplitter is 5 ]Sa#g&}T>
this("","","",5); 8]`s&d@GY
} YlGUd~$`"+
yUpN`;
YI"!&a'yj
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) X';qcn_^
{ V6HZvuXV!
sSiteURL= sURL; jQ%1lQ#R)
sFilePath = sPath; "5 ~{
sFileName = sName; sCzpNJ"8
this.nSplitter = nSpiltter; Zy;jp*Q
HJ]e%og
1Td`S1'#yg
} .S#i/A'x
iQ8{N:58DN
-Pt E+R[A
public String getSSiteURL() RH _b
{ r"h09suZBW
return sSiteURL; Z$KyK.FUU
} %N~c9B
W,Q>3y*
RMT9tXe*5
public void setSSiteURL(String value) 7sOAaWx
{ F9K`N8wlu
sSiteURL = value; iv6G9e{cx
} ,&=7ir14>R
Xn%7{%;h
%H"
public String getSFilePath() 5CN=a2&
{ JmK )Y# A
return sFilePath; %M'`K
} wzwv>@}
\i//Aq
8w:mL^6x
public void setSFilePath(String value) __QnzEF
{ 8~-TN1H
sFilePath = value; 3))R91I
} Ua 6O~,\
OEjX(F3=
H,w8+vZ4\
public String getSFileName() wZ\93W-}
{ X;6;v]
return sFileName; #xu1 eX0<
} 6O6B8
\:1$E[3v
sfw*_}y
public void setSFileName(String value) x,10o
{ &`n:AR`
sFileName = value; z8}QXXa
} .$x}~Sw
9v*y&V9/
JluA?B7E
public int getNSplitter() Tr:@Dv.O
{ oYf+I
return nSplitter; juWXB+d2Y
} pqpsa'
jFe8s@7
vvxD}p=y
public void setNSplitter(int nCount) Lv/}&'\(
{ )rj!/%
nSplitter = nCount; 5~DKx7P!Z
} L3wj vq^
} ]oSx]R>{f
^K1mh9O
xPUukmG:B
/* NJr)f
**Utility.java zNKB'hsK
*/ H.{Fw j4
package NetFox; Ayqs~&{
4C_1wk('
5!Y\STn
public class Utility { Wc+(xk
:KX*j$5U
|&WYu,QQ4
public Utility() O]hUOc`k
{ ,z#D[5
Hkia&nz'3
UF5_be,D
} 5p!{#r6m
NwYQ6VEA
//线程睡眠 I F!xZ6X8
public static void sleep(int nSecond) 2'M5+[8y8
{ i7h^L)M
try{ Vfy@?x= &
Thread.sleep(nSecond); p7`9 d1n
} _/>I-\xWA
catch(Exception e) &0Y |pY
{ +<xQF
e.printStackTrace (); @"fv[=Xb
} !=.y[Db=
} eza"<uBr
YzZj=]\`b
//日志 CStNCBZ|\
public static void log(String sMsg) kn>qX{W
{ ]rY9t@
System.err.println(sMsg); 'G % ]/'_U
} cW0\f5[/
VM<0_R24z
F{ vT^/
public static void log(int sMsg) ZR3,dW6S
{ 8h|}Q_
System.err.println(sMsg); sRcd{)|Cq
} g_l-@
} (oy@j{G)c6
ojBdUG\
i.On{nB"k
/* !F}GSDDV*
**TestMethod.java ?F[_5ls|]
*/ JLWm9c+UTG
package NetFox; 6%6dzZ
X!z-J>
~1*37w~
public class TestMethod { |*zgX]-+;
HX| p4-L
r]\[G6mE%
public TestMethod() JiXE{(
{ ///xx/weblogic60b2_win.exe P6>C+T1
try{ -WyB2$!(
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); cL4Go,)w
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); S m=ln)G=
SiteFileFetch fileFetch = new SiteFileFetch(bean); \^y~w~g?
fileFetch.start(); X}3?k<m
} v:74iB$i/C
catch(Exception e){e.printStackTrace ();} RLQ*&[A}
s1Wn.OGR4
hC<E4+5.,
} mpwh=
{_\dwe9
5X];?(VTsb
public static void main(String[] args) Px?"5g#+
{ u|$HA>F[
new TestMethod(); A~E S{Zkh
} 8irTGA
} +[n#{;]<
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