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)); =$\9t$A
} |6b&khAM
for(int i=0;i<nEndPos.length-1;i++) Ko %e#q-
{ Ypx"<CKP}
nEndPos = nStartPos[i+1]; 4.q^r]m*
} *+j r? |
nEndPos[nEndPos.length-1] = nFileLength; noO#o+ Jg#
} )^j62uv
} >ui;B$=
hWRr#030
Tvd: P^C
//启动子线程 G/yYIs
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; Z8\/Fb
for(int i=0;i<nStartPos.length;i++) G)&S%R!i\N
{ uevhW
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), Er<!8;{?
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), [s~6,wz
nStartPos,nEndPos,i); x+,:k=JMT
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); TECp!`)j"
fileSplitterFetch.start(); |eP5iy wg
} FR6PY
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 'oF('uR
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); !Mj28
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", b$>1_wTL
nEndPos = " + nFileLength); Lm'+z97
// fileSplitterFetch[nPos.length-1].start(); oh,29Gg
=s,}@iqNO4
? w@)3Z=u
//等待子线程结束 & DhdB0Hjf
//int count = 0; .T#}3C/
//是否结束while循环 E*d UJ.>
boolean breakWhile = false; !3 zN [@w,
Ceew~n{
rYrvd[/*&(
while(!bStop) %g~zEa-g
{ \/R $p
write_nPos(); 0t6DD
Utility.sleep(500); Te7xj8<
breakWhile = true; =!IoL7x
_a zJ>
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for(int i=0;i<nStartPos.length;i++) !JA//{?
{ Qn)AS1pL+
if(!fileSplitterFetch.bDownOver) &A~hM[-
{ hY|-l%2f
breakWhile = false; e;9x%kNs!
break; Mt&n|']`8
} M# cJ&+rP
} gPIl:, d(
if(breakWhile) m[s$)-T
break; DC2[g9S>8@
6bT>x5?
T%w5%{dqJ
//count++; Y-~MkB
//if(count>4) =-/sB>-C
// siteStop(); ;3+_aoY
} bmO(tQS$5
r\FduyOXv
qD,/Qu62
System.err.println("文件下载结束！"); Dw<bLSaW&
} xMFEeSzl>S
catch(Exception e){e.printStackTrace ();} sCE%./h]
} g1)ZjABV
{TaYkuWS
F[>Y8e<[
//获得文件长度 >S]"-0tGD=
public long getFileSize() D+{&zo
{ ba^/Ar(B
int nFileLength = -1; \6%`)p
try{ 6_>(9&g`zV
URL url = new URL(siteInfoBean.getSSiteURL()); 2Mj_wc
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); M"yOWD~s~
httpConnection.setRequestProperty("User-Agent","NetFox"); o,{]<Sm
me$nP}%C&
'u6n,yRm
int responseCode=httpConnection.getResponseCode(); a&u!KAQ
if(responseCode>=400) _}tPtHPa/
{ B(Er/\-@U
processErrorCode(responseCode); HJt '@t=Ak
return -2; //-2 represent access is error ,>Dpt<
} }H|'W[Q.
=ba1::18
5-UrHbpCZ#
String sHeader; &FWz7O>1
DC0ON`
?*'0;K13
for(int i=1;;i++) Ru4M7%
{ u@t~*E5BpM
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); >v)V2,P -
//Utility.log(in.readLine()); <Df2
sHeader=httpConnection.getHeaderFieldKey(i); \=Od1i
if(sHeader!=null) 8L5O5F'
{ gObafIA
if(sHeader.equals("Content-Length")) K|=va>
{ ~U5Tn3'~
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); S}qGf%
break; 15d'/f
} -K/c~'%'*
} f6 s .xQ
else M"6J"s
break; hx ^l
} 0bOT&Z^
} ua,!kyS
catch(IOException e){e.printStackTrace ();} #44}Snz
catch(Exception e){e.printStackTrace ();} QwL*A `@
M5 ^qc
z>)lp$
Utility.log(nFileLength); `nY.&YT
1'|gxYT
NdrR+t^#
return nFileLength; lv+: `
} uZ'(fnZ$
^DVryeLD
e$E>6Ngsr
//保存下载信息（文件指针位置） jwSPLq%
private void write_nPos() p-H}NQ\
{ T[MDjhv'
try{ a*uG^~ ).
output = new DataOutputStream(new FileOutputStream(tmpFile)); 1\nzfxx
output.writeInt(nStartPos.length); ^ 4*#QtO
for(int i=0;i<nStartPos.length;i++) s"p\-Z
{ W)8Pq9Hnv
// output.writeLong(nPos); TeFi[1
output.writeLong(fileSplitterFetch.nStartPos); 4gZ)9ya
output.writeLong(fileSplitterFetch.nEndPos); \["I.gQ
} b*ja,I4
output.close(); ;te( {u+
} T8d=@8g,%
catch(IOException e){e.printStackTrace ();} Dw$RHogb~y
catch(Exception e){e.printStackTrace ();} g!OcWy)7
} `26.+>Z7
bz.sWBugR
-]{ _^
//读取保存的下载信息（文件指针位置） XBB>"
private void read_nPos() BPm")DMo
{ 4'`H H
try{ N9s.nu
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); xg8R>j
int nCount = input.readInt(); ma!C:C9#J
nStartPos = new long[nCount]; f`_{SU"3
nEndPos = new long[nCount]; %d40us8E
for(int i=0;i<nStartPos.length;i++) {d]B+'
{ QDVSFGwr
nStartPos = input.readLong(); 7FD,TJs
nEndPos = input.readLong(); hl] y):
} ,-8Xb+!8I
input.close(); fY?:SPR+
} R y(<6u0
catch(IOException e){e.printStackTrace ();} !VsdKG)
catch(Exception e){e.printStackTrace ();} ~4Mz:h^
} s&Al4>}.f
r`.Bj0
>j*0fb!:]
private void processErrorCode(int nErrorCode) F9d6#~
{ %s9*?6
System.err.println("Error Code : " + nErrorCode); 13)6p|6x
} 9ZR"Lo>3e+
*uP;rUY
%++S;#)~
//停止文件下载 Aq7`A^1t$
public void siteStop() .F2"tt?'
{ {7MY*&P$,
bStop = true; >Q^ mR
for(int i=0;i<nStartPos.length;i++) o4@d,uIw^
fileSplitterFetch.splitterStop(); W(?J,8>
6c27X/'Z
lbw+!{Ch
} "}ur"bU1
} x1STjI>i
//负责部分文件的抓取 mA_EvzXk\
**FileSplitterFetch.java n "^rS}Y]
*/ 4>fj@X(3
package NetFox; m!!;CbPo
k>8OxpaWv?
*f{4_ts
import java.io.*; p]?eIovi
import java.net.*; WE_'u+!B
8wZ $Hq
7}~nQl2
public class FileSplitterFetch extends Thread { YcR: _ac
~k?t
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String sURL; //File URL ,zH\P+*
long nStartPos; //File Snippet Start Position 0}'/pN>
long nEndPos; //File Snippet End Position 3UZ_1nY
int nThreadID; //Thread's ID 1rU\ !GfR
boolean bDownOver = false; //Downing is over =,i?8Fuz
boolean bStop = false; //Stop identical eb,QT\/G
FileAccessI fileAccessI = null; //File Access interface ^L Xr4
W?.xtQEv
mz;ExV16
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException z~v-8aw
{ {l_D+B;
this.sURL = sURL; [xDIK8d:I
this.nStartPos = nStart; {_z6
this.nEndPos = nEnd; sk~7"v{Y.
nThreadID = id; W=|'&UU Ul
fileAccessI = new FileAccessI(sName,nStartPos);//定位 IBNb!mPu%
} y^kC2DS
#-R]HLW*
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public void run() W&Xi&[Ux
{ r8FAV9A
while(nStartPos < nEndPos && !bStop) !}1l8Y
{ ?6I`$ &OA
I>-}ys`[
gq~`!tW'
try{ [`KQ\4u
URL url = new URL(sURL); OT)`)PZ"
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); TLVfu4
httpConnection.setRequestProperty("User-Agent","NetFox"); p{SIGpbR&
String sProperty = "bytes="+nStartPos+"-"; 6+PP(>em
httpConnection.setRequestProperty("RANGE",sProperty); [r'hX#
Utility.log(sProperty); "e29j'u!*
)coA30YR
.Dr7YquW
InputStream input = httpConnection.getInputStream(); }JT&lyO< b
//logResponseHead(httpConnection); l|9'l[}&
YsO`1D
do%.KIk
byte[] b = new byte[1024]; :n x;~f
int nRead; u9+)jN<Yh
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) )*o) iN 7l
{ j{zVVT
nStartPos += fileAccessI.write(b,0,nRead); ~i}/
//if(nThreadID == 1) tfe'].uT
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); ?C6`
} !W=2ZlzS
FOcDBCrOe
I+Fr#1
Utility.log("Thread " + nThreadID + " is over!"); `]Vn[^?D
bDownOver = true; o%Qn%gaX
//nPos = fileAccessI.write (b,0,nRead); a1weTn*
} 2Ju,P_<dt
catch(Exception e){e.printStackTrace ();} OQT i$2
} |C t Q
} $g#d1u0q
rO1.8KKJ
r1$x}I#Zv
//打印回应的头信息 <5sfII
public void logResponseHead(HttpURLConnection con) -%t8a42
{ Y XxWu8
for(int i=1;;i++) 6AmFl<
{ [3W+h1
String header=con.getHeaderFieldKey(i); "QY~V{u5
if(header!=null) Szlww
//responseHeaders.put(header,httpConnection.getHeaderField(header)); UAdj[m61
Utility.log(header+" : "+con.getHeaderField(header)); /bqJ6$
else /3~}=b
break; aK9zw
} h6(L22Hn
} z.kBQ{P
VH.}}RS%
u+8?'ZT,
public void splitterStop() t]pJt
{ C6b(\#g(
bStop = true; c1_?Z
} 9M-/{D^+<
e9?y0vT//
yAVt[+0
} %] 7.E
z[_Gg8e
R )e^H
/* H\e<fi%Q
**FileAccess.java :y[tZ&*<_?
*//文件访问(定位，写) px_%5^zRQ
package NetFox; z3-AYQ.H
import java.io.*; MT@Uu
S8Yh>j8-
aw/5#(1R
public class FileAccessI implements Serializable{ Ehf{Kl
n?A;'\cK
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 ZpY"P6
RandomAccessFile oSavedFile; K3t^y`z
long nPos; L"!BN/i_
9Uh nr]J.
:YZMRJL
public FileAccessI() throws IOException \>-%OcYlM
{ bwh.ekf8
this("",0); PK* $
} yf6&'Y{
b}r3x&)
[t`QV2um
public FileAccessI(String sName,long nPos) throws IOException nS1D&;#Y
{ >j$CM:w
oSavedFile = new RandomAccessFile(sName,"rw"); BK]q^.7+:
this.nPos = nPos; sxLq'3(
oSavedFile.seek(nPos); /fc@=CO
} }mC-SC)oSi
%fz!'C_4
`4 A%BKYB
public synchronized int write(byte[] b,int nStart,int nLen) 4<&`\<jZ
{ %/&?t`%H
int n = -1; u|D_"q~+6
try{ I(Yyg,1Z
oSavedFile.write(b,nStart,nLen); *^u5?{$l(
n = nLen; Tce2]"^;
} y(8AxsROp
catch(IOException e) R@r"a&{/
{ y85/qg)H^
e.printStackTrace (); 5!G}*u.
} /wL}+
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S:Ne g!`
return n; :_Y@,CpIEg
} fNx3\<~V=
eVDI7W:(Sn
pVt8z|p_;{
} b^\u P
|,Y(YSg.
xS`>[8?3<T
/* ^60BQ{ne
**SiteInfoBean.java iFW)}_.
*/ Q': }'CI
package NetFox; ^l6q
?y7x#_Exc
`2?9eXC
public class SiteInfoBean { :'!,L0I|t
kQ~*iY
$aX}i4F
private String sSiteURL; //Site's URL BXVmt!S5F
private String sFilePath; //Saved File's Path Sf)VQ5U!Y
private String sFileName; //Saved File's Name 2mbZ6'p {
private int nSplitter; //Count of Splited Downloading File 4*_9Gl
M yr [
=LS?:Mhm
public SiteInfoBean() jyf[O -
{//nSplitter的缺省值为5 Qd 1Q~PBla
//default value of nSplitter is 5 ]dc^@}1bN
this("","","",5); &V[m{.
} q7C>A`w
XU .FLNe
WLEjRx
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) RJ1Q.o
{ -1~bWRYq
sSiteURL= sURL; Mjrl KI}f/
sFilePath = sPath; $z]gy]F
sFileName = sName; Cw`v\ 9
this.nSplitter = nSpiltter; E3y"
g&H6~ +\
ewSFB< N
} T"XP`gk
G_g~-[O
J A ]s
public String getSSiteURL() auqM>yx
{ ao<@a{G
return sSiteURL; BM#cosV7%h
} UfSWdR)
j9sf~}D>
[: X
public void setSSiteURL(String value) *BT-@V.4
{ ojzO?z
sSiteURL = value; 2![.Kbqa%
} 6yKr5tH4
6e$(-ai
wGE:U`
public String getSFilePath() cejSGsW6q
{ C XZm/^
return sFilePath; n0kBLn
} NWSBqL5v
q3B#rje>h
[ottUS@
public void setSFilePath(String value) O2?ye4uq
{ ._"U{ f2V
sFilePath = value; ](4V3w.
} ;OQ{
|0ahvsrtW
Funep[rA
public String getSFileName() 3HC aZ?Ry'
{ v&%GK5j7O
return sFileName; ]FvN*@lG
} ? r=cLC
Sve~-aG
H?8KTl=e
public void setSFileName(String value) JNRG[j
{ r@0HqZx`
sFileName = value; ]QM6d(zDA
} )Fk%,H-1
=9GL;z:R+
0Np}O=>
public int getNSplitter() 9`+c<j4/B
{ UwrinkoeE
return nSplitter; *[(O&L&0
} &Jv j@,>$d
^)conSm
5V4Ze;K
public void setNSplitter(int nCount) z,[4BM
{ |AW[4Yn>
nSplitter = nCount; P*XLm
} K_',Gd4L
} V6?ku6k
$%"i|KTsv:
1 e1$x@\\
/* IL?3>$,
**Utility.java gYfN?A*`_
*/ v_"p)4&'
package NetFox; 8MGtJ'.
{3]g3mj
hWwh`Vw%
public class Utility { 1+v&SU
*<#jr
4:=']C
public Utility() Tk9u+;=6$
{ >nkd U
MQY^#N
L"A,7@:Vd
} a33}CVG-e3
',?v7&
//线程睡眠 kXA o+l
public static void sleep(int nSecond) aErms-~
{ \,i9m9;y
try{ aG}ju;
Thread.sleep(nSecond); : I28Zi*
} ao#{N=mn
catch(Exception e) s\,F6c
{ gEbe6!; q3
e.printStackTrace (); a H'iW)
} QpwOrxI}
} 6uW?xB9
,J"6(nk
//日志 EFu2&P
public static void log(String sMsg) &WE|9
{ j1%o+#df
System.err.println(sMsg); d76k1-m\o
} l9"0Wu@_x
3~}G~ t
[URo#
public static void log(int sMsg) hC?:XVt
{ $As;Tvw.
System.err.println(sMsg); @|v4B[/
} u~7mH
} xV[X#.3
OF&{mJH"g'
xQ9P'ru
/* M?Tb9c?`
**TestMethod.java T_|%nF-+
*/ %bgjJ`
package NetFox; "i_I<?aGB
~+}w>jIm{|
S#6{4x4
public class TestMethod { Fxdu)F,~u
qk;*$Q
u+UtvzUC
public TestMethod() b}< T<
{ ///xx/weblogic60b2_win.exe x.CUJ^_.
try{ q`_d>l
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); (+q#kKR
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); >=BH$4Ce
SiteFileFetch fileFetch = new SiteFileFetch(bean); 2K4Jkyi
fileFetch.start(); b<>GF-`w
} :kz*.1
catch(Exception e){e.printStackTrace ();} _^;+_6&[
GOuBNaU{
U>?q|(u
} m/RX~,T*v&
a~E@scD
Qn'Do4Le
public static void main(String[] args) NC'+-P'y
{ Z&9MtpC+N3
new TestMethod(); 1$T;u~vg
} k=1([x
} al/Mgo
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