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)); i4M%{]G3Y
} =&DuQvN,
for(int i=0;i<nEndPos.length-1;i++) >Dz8+y
{ Tiimb[|
nEndPos = nStartPos[i+1]; Wo,93]
} sNMF(TY
nEndPos[nEndPos.length-1] = nFileLength; E#!.;AQ
} w")m]LV
} x]4>f[>*>
/R>YDout}
]a[2QQ+g
//启动子线程 3bQq Nk
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; JLg/fB3%
for(int i=0;i<nStartPos.length;i++) jc,Qg2
{ 1Cw$^jd
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), .;(a;f+{;
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), kX)*:~*
nStartPos,nEndPos,i); I<Mb/!TQ
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); Il#ST
fileSplitterFetch.start(); yDj'')LOQg
} _'n]rQ'
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), Rh)%;
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); T#vY(d
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", $P2*qpqy
nEndPos = " + nFileLength); ^SM5oK
// fileSplitterFetch[nPos.length-1].start(); D'^UZZlI^I
{]dvzoE]
|C0!mU
//等待子线程结束 X}ihYM3y/
//int count = 0; J5z\e@?.0\
//是否结束while循环 B$S@xD $
boolean breakWhile = false; Y)#,6\=U
[/<kPi
Oh,Xjel
while(!bStop) 9Sl5jn
{ }j!C+i
write_nPos(); CdtCxy5
Utility.sleep(500); 5'<a,,RKu
breakWhile = true; vN~joQ=d
43~v1pf{!
-M4VC^_
for(int i=0;i<nStartPos.length;i++) /_yAd,^-+
{ CBz=-Xr
if(!fileSplitterFetch.bDownOver) w@\4ft6d
{ +k0UVZZX?
breakWhile = false; r"t,/@`n
break; D z[,;
} -"XHN=H
} .B'ws/%5\
if(breakWhile) BJ5^-|
break; z f>(Y7M
!P":z0K4
Bw9O)++
//count++; xU(b:D Z
//if(count>4) o>&-B.zq
// siteStop(); 5v sn'=yN
} =Wz)(N
def\=WyK
m\_v{1g
System.err.println("文件下载结束！"); ?=HoU3
} Owv}lJ
catch(Exception e){e.printStackTrace ();} 3{TE6&HIa
} 8x8nQ*_
AtqsrYj
PO|gM8E1x?
//获得文件长度 M<SVH_
public long getFileSize() 1bjWWNzQA
{ ):n'B` f}z
int nFileLength = -1; eQMa9_
try{ 6QNZ/Ox:
URL url = new URL(siteInfoBean.getSSiteURL()); ,pUB[w\
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); HHOqJb{8S
httpConnection.setRequestProperty("User-Agent","NetFox"); :!FGvR6
s%A?B8,
=dp`4N
int responseCode=httpConnection.getResponseCode(); V|/N-3M
if(responseCode>=400) db>"2EE
{ }|nEbM]#
processErrorCode(responseCode); f?(g5o*2
return -2; //-2 represent access is error vtc%MG1
} iT+t
H;+98AIy`
bP%X^q~]A
String sHeader; lXD=uRCI
?/(*cA
n;>r
for(int i=1;;i++) ?`75ah
{ biU ?>R
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); []?*}o5&>T
//Utility.log(in.readLine()); G)gb5VW k
sHeader=httpConnection.getHeaderFieldKey(i); '}q/;}ih
if(sHeader!=null) lQ4$d{m`
{ 7Oi<_b
if(sHeader.equals("Content-Length")) ]1I-e2Q-J
{ {5+ 39=(
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); .s|5AC[
break; >xXq:4l>}
} {yMkd4v
} wp@6RJ
else Zj0h0Vt
break; }s8xr>
} 4z^~,7J^
} g9IIC5
catch(IOException e){e.printStackTrace ();} iL~(BnsF
catch(Exception e){e.printStackTrace ();} BU|m{YZ$
GbvbGEG
d-gcXaA-8
Utility.log(nFileLength); YI]/gWeu
nd5.Py$
!"ydl2
return nFileLength; AR g]GV/L
} y4H/CH$%
8rNf4]5@X(
}$a*XY1
//保存下载信息（文件指针位置） EWWCh0 {
private void write_nPos() IcNZUZGE
{ m`4N1egCt
try{ vJ;0%;eu[!
output = new DataOutputStream(new FileOutputStream(tmpFile)); BM87f:d
output.writeInt(nStartPos.length); `'pfBVBz
for(int i=0;i<nStartPos.length;i++) A^4#6],%v
{ w!}kcn<
// output.writeLong(nPos); C]3^:b+
output.writeLong(fileSplitterFetch.nStartPos); uTy00`1
output.writeLong(fileSplitterFetch.nEndPos); gGs"i]c
} T6\d]
output.close(); 4OG1_6K
} V! .I>
catch(IOException e){e.printStackTrace ();} 8C I\NR{x8
catch(Exception e){e.printStackTrace ();} -JclEp
} p1IN%*IV+o
,5x9o"N!
9q2x}
//读取保存的下载信息（文件指针位置） v}@Uc-(
private void read_nPos() `*B6T7p1
{ gj }Vnv1[
try{ M0]J`fL@
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); @2+'s;mUV
int nCount = input.readInt(); WHRBYq_
nStartPos = new long[nCount]; MQX9BJ%
nEndPos = new long[nCount]; "~"=e
for(int i=0;i<nStartPos.length;i++) /5?tXH"
{ |#B)`r8
nStartPos = input.readLong(); ) LohB,?
nEndPos = input.readLong(); Y*S(uqM
} ^>z+e"PQA
input.close(); Y{8}z ZD
} Uu|R]azbO
catch(IOException e){e.printStackTrace ();} z%$M IC
catch(Exception e){e.printStackTrace ();} c >xHaA:V
} u>V~:q\X
^KQZ;[B
Kw`}hSE>o
private void processErrorCode(int nErrorCode) cq$_$jRx
{ L; <Pod
System.err.println("Error Code : " + nErrorCode); fhro"5/4
} RuOse9
Ubh)}G,Mg
\CYKj_c
//停止文件下载 xBE}/F$45
public void siteStop() 5zF$Q{3
{ '.7ER
bStop = true; ,fhK
for(int i=0;i<nStartPos.length;i++) 3WPZZN<K9
fileSplitterFetch.splitterStop(); 7<LCX{Uw
4^ZbT
@\U] hN?
} I@(3~ Ab
} 12}!oS~_
//负责部分文件的抓取 n_6#Df*
**FileSplitterFetch.java _I0=a@3
*/ ye4GHAm,p
package NetFox; 3O|2Z~>3
0*KL*Gn
yxi*4R
import java.io.*; ,S&p\(r.
import java.net.*; D*g K,`
m=60a@o]
$,nidK!"
public class FileSplitterFetch extends Thread { <_SdW 5BF<
?:+p#&I
e[db?f2!
String sURL; //File URL 4Gj
long nStartPos; //File Snippet Start Position 2F/oWt|w?
long nEndPos; //File Snippet End Position ((6?b5[
int nThreadID; //Thread's ID j/1f|x
boolean bDownOver = false; //Downing is over $|I hO
boolean bStop = false; //Stop identical <Kk?BRxi
FileAccessI fileAccessI = null; //File Access interface |J~A )Bw?
KBgFS%-W
u&e?3qKX(
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException H?;@r1ZAn
{ i4)]lWnd
this.sURL = sURL; {`9J8qRY
this.nStartPos = nStart; 5m?9O7Pg
this.nEndPos = nEnd; [f]:hJi
nThreadID = id; }synU]^7\
fileAccessI = new FileAccessI(sName,nStartPos);//定位 ,hCbx#h
} hSaw)g`w
C-H6l6,
k>:\4uI|<\
public void run() QiNLE'19^
{ 8TYoa:pZ
while(nStartPos < nEndPos && !bStop) w]US-7
{ Q}1qt4xy*
{&nDm$KTD
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try{ +ux`}L(
URL url = new URL(sURL); Li\b,_C
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); y)3OQ24
httpConnection.setRequestProperty("User-Agent","NetFox"); Lv *USN
String sProperty = "bytes="+nStartPos+"-"; fBKN?]BdN
httpConnection.setRequestProperty("RANGE",sProperty); fbkAu
Utility.log(sProperty); 22`e7
/`7G7pQ+
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InputStream input = httpConnection.getInputStream(); g>{t>B%v^K
//logResponseHead(httpConnection); 9} ]C
o}yA{<"
U:8cz=#
byte[] b = new byte[1024]; 7/dp_I}cO
int nRead; 3(1UIu
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) 7Kti&T
{ ;ih;8
nStartPos += fileAccessI.write(b,0,nRead); y 48zsm{
//if(nThreadID == 1) Jjh=zxR>
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); bs)Ro/7}
} 3vEwui-5
M+7jJ?n
1(jx.W3
Utility.log("Thread " + nThreadID + " is over!"); 'i 8`LPQ
bDownOver = true; t!0 IQ9\[*
//nPos = fileAccessI.write (b,0,nRead); tNxKpA |F
} cK'}+
catch(Exception e){e.printStackTrace ();} MgHO WoF
} LqS_%6^
} K\5/||gi
~_ko$(;A
}jYVB|2
//打印回应的头信息 kM3#[#6$!
public void logResponseHead(HttpURLConnection con) .<6'*XR
{ :PBW=W
for(int i=1;;i++) ![m6$G{y
{ A9LVS&52
String header=con.getHeaderFieldKey(i); ^h"@OEga?
if(header!=null) 'NDr$Qc3
//responseHeaders.put(header,httpConnection.getHeaderField(header)); JC7:0A^
Utility.log(header+" : "+con.getHeaderField(header)); P@U2Q%\
else ;6*$!^*w
break; _hEr,IX=J
} ^-(DokdBn
} i_p-|I:hQ
,jeC7-tX
Bm&6
public void splitterStop() 1/c+ug!y
{ =lx~tSiS
bStop = true; TmJXkR.5
} %t]{C06w+{
SxL/]jWR7
kk}_AZ0eK
} |q Pu*vR
z]!w@:
[$Jsel<T=
/* t_\&LMD
**FileAccess.java 1?,C d
*//文件访问(定位，写) vHb^@z=
package NetFox; h/*@ML+bB8
import java.io.*; "lL/OmG
5JS*6|IbD{
Ij:yTu
public class FileAccessI implements Serializable{ Twk<<
*C.Kdf3w
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 &5hs W1`
RandomAccessFile oSavedFile; gq~"Z[T
long nPos; f0*_& rP
ow#8oUf=
,Uy;jk
public FileAccessI() throws IOException i\=I` Yn+
{ wqgKs=y
this("",0); Nop61zj
} $}=r45e0K
xp*d:
)*aAkM
public FileAccessI(String sName,long nPos) throws IOException =Ea,8bpn
{ '30JJ0
oSavedFile = new RandomAccessFile(sName,"rw"); ulfs Z:
this.nPos = nPos; w4l]rH
oSavedFile.seek(nPos); tMyMA}`
} 7t+H94KG7
N:,V{Pw
=FfR?6 ~
public synchronized int write(byte[] b,int nStart,int nLen) l|M|;5TW
{ E CPSE{
int n = -1; "e/"$z'ca
try{ !(y(6u#
oSavedFile.write(b,nStart,nLen); !p_l(@f
n = nLen; \!*F:v0g^
} ,q$2D,dz
catch(IOException e) ~w(A3I.
{ ^=qV)j
e.printStackTrace (); S`vw<u4t
} z2q!_ ~
,I:[-|Q
S(lqj6aa}
return n; WN o+%
} *Zn,v-d
qipS`:TER
%cASk>^i
} 2~hQ
-o57"r^x
`0-i>>
/* nWUau:%
**SiteInfoBean.java jn oX%3d-
*/ 4thPR}DH}
package NetFox; %m$t'?
!ED,'d%J
@Y#TWt#
public class SiteInfoBean { )2r_EO@3HP
ZL9|/ PY
eGo$F2C6E
private String sSiteURL; //Site's URL },#AlShZu
private String sFilePath; //Saved File's Path 2t7=GA+j
private String sFileName; //Saved File's Name >Fc=F#tA9
private int nSplitter; //Count of Splited Downloading File 5,R<9FjW
1h`#H:
!X=93%
public SiteInfoBean() oOGFg3X
{//nSplitter的缺省值为5 '(8} <(%
//default value of nSplitter is 5 d%oHcn
this("","","",5); {3 >`k.w
} ,fj~BkW{
T? ,Q=.
#vTF:r
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) 6>h"Lsww
{ |2I p*
sSiteURL= sURL; 4hUUQ;xj
sFilePath = sPath; bLUyZ3m!
sFileName = sName; _;-b ZH
this.nSplitter = nSpiltter; -U@ycx|r
axv-UdE;
"rw'mogRL
} 7QaZ|\c
A$TFa:O|
Q|Nw @7$`
public String getSSiteURL() p(A[ah_
{ E,[v%Xw
return sSiteURL; s$/Z+"f(
} 4rD&Lg'
Y7`Dx'x
$EZr@n
public void setSSiteURL(String value) RG-,<G`
{ x^ sTGd
sSiteURL = value; t0)hdX
} EtDzmpJR>
`>`{DEDx{5
7[8d-Sf24{
public String getSFilePath() Vje LPbk)
{ &lW~ot1,
return sFilePath; 7Y^2JlZu=
} 'zuA3$SR
$oZV 54
mMad1qCi7
public void setSFilePath(String value) 5 Praj
{ 3 FLht L
sFilePath = value; g+=f=5I3
} a<Ps6'
$HV`bJ5!L*
a6g+"EcH#'
public String getSFileName() hle@= e/n
{ }k6gO0z
return sFileName; <:~'s]`zf
} M_\)<a(8
bd`}2vr
=z2g}X
public void setSFileName(String value) >8DZj&j
{ -)E6{
sFileName = value; mQ:5(]v
} PL*kjrLu7
|A:+[35
o&rNM5:
public int getNSplitter() :4S~}}N
{ MT.D#jv&
return nSplitter; 5i&+.?(Z=
} (%|L23
q]z%<`.9*
uJ%XF*>_D
public void setNSplitter(int nCount) | PzXN+DW
{ zvh&o*\2<d
nSplitter = nCount; *7!*kqg!u
} l1}HJmom
} i>AKXJ+
08;t%[R
~@EBW3>~5
/* \ dZD2e4
**Utility.java F$H^W@<w
*/ SR&'38UCe
package NetFox; ^+Stvj:N
mX QVL.P\
.k:Uj-&
public class Utility { |[ ,|S{
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tU(vt0~b
public Utility() uHpSE?y/
{ )x&OdFX
e=EM07z
_;`g*Kx
} )l*6zn`z
uOnyU+fZV
//线程睡眠 >&2n\HR\
public static void sleep(int nSecond) +G<9|-
{ ,daZKxT
try{ <{b#nPc!,#
Thread.sleep(nSecond); +UC-
} X|X~|&j
catch(Exception e) ?*)wQZt;
{ 'CO3b,
e.printStackTrace (); Na2n4x!
} G/5]0]SO
} ^J$?[@qD
/J0ctJ2k
//日志 Cz1o@rt
public static void log(String sMsg) 60&4?<lR4
{ - d(RK_
System.err.println(sMsg); [EU\-
} $mp'/]
_f5n t:-
J`4{O:{4
public static void log(int sMsg) U:o(%dk
{ $S _VR
System.err.println(sMsg); fA>FU/r
} wX*F'r"z
} W6[# q%o
dF/HKBJ
^-i<TJ
/* `;fk,\8t%
**TestMethod.java X0QLT:J b
*/ -^%YrWgd?
package NetFox; XKq}^M&gy
NN;'QiE
J|A:C[7 2
public class TestMethod { RY]Vo8
^sA"&Vdr^
F ak"u'~
public TestMethod() M;Dk$B{;R
{ ///xx/weblogic60b2_win.exe 6$|!_94>*)
try{ ~9KxvQzt
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); j\S}TaH0e
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); -h/KrB
SiteFileFetch fileFetch = new SiteFileFetch(bean); {a `#O9
fileFetch.start(); P,@ :?6
} 8P#jC$<
catch(Exception e){e.printStackTrace ();} xfyUT^
4dwG6-
_;1H2o2f
} ;.<0lnV
8={"j
}.j09[<
public static void main(String[] args) iHB1/
{ g,N"o72)
new TestMethod(); sC=fXCGW\p
} *j0kb"#
} jg_##Oha
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