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)); 5OEo(&
} a8 X}r.
for(int i=0;i<nEndPos.length-1;i++) #IJm*_J<
{ 44Dytpvg
nEndPos = nStartPos[i+1]; Lk%`hsv
} CFE ubEb
nEndPos[nEndPos.length-1] = nFileLength; &T.d"i
} G47(LE"2b
} !8g419Yg
@*?)S{8
/my5s\;s|z
//启动子线程 z<_&4)2{
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; *Bfo"["0.
for(int i=0;i<nStartPos.length;i++) \c')9g@
{ `iHyGfm
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 8^IV`P~2M
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), zM+4<k_dH]
nStartPos,nEndPos,i); LZ#=Ks
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); pbCj ^
fileSplitterFetch.start(); {6 #Qm7s-
} -VZn`6%s
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), jY;T:C-T
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); TxJoN]Z.
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", 1`hmD1d
nEndPos = " + nFileLength); oX=dJJE
// fileSplitterFetch[nPos.length-1].start(); v~8CpC
8F>u6Y[P
@},|i*H/
//等待子线程结束 R*[X. H
//int count = 0; 9Lus,l\
//是否结束while循环 [T |P|\M
boolean breakWhile = false; N5PW]
-L-#-dK'
Ky0}phGRu
while(!bStop) 2xLEB&
{ 3Pu8IXW
write_nPos(); # &,W x
Utility.sleep(500); 1NAGGr00
breakWhile = true; Fqt,VED
18^#:=Z
l4s*+H$vd?
for(int i=0;i<nStartPos.length;i++) jKh:}yl4
{ r` B(ucE
if(!fileSplitterFetch.bDownOver) D`|8Og
{ L@5sY0 M
breakWhile = false; }SfS\b{|~
break; A%[e<vj9
} reQr=OAez
} -F. c<@*E
if(breakWhile) 8Y]% S9.
break; qX[{_$^Q
>&DC[)28
pV8_i7\
//count++; nND; lVQSO
//if(count>4) Z~0TO-Q
// siteStop(); lRk_<A
} mEm=SpO[$o
t[e]AU[}
LR "=(
System.err.println("文件下载结束！"); XF&_**0n
} `@q\R-`
catch(Exception e){e.printStackTrace ();} E2xK GK
} PglSQ2P
<4LW.q
F?z:[1(:
//获得文件长度 rp '^]Zx
public long getFileSize() )3IUKz%\6p
{ ,i jB3J
int nFileLength = -1; |.4>#<$__
try{ Vp7d
URL url = new URL(siteInfoBean.getSSiteURL()); MY60%
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); C'y4 ~7
httpConnection.setRequestProperty("User-Agent","NetFox"); `fuQt4
s=e`}4
DPlDuUOd
int responseCode=httpConnection.getResponseCode(); f,|g|&C
if(responseCode>=400) hgj ]Jr
{ 0 <E2^
processErrorCode(responseCode); eB&.keO
return -2; //-2 represent access is error qfkdQ/fP
} y7t'I.E[+
\0W0o5c$
v<Ywfb
String sHeader; Jc7}z:UB
=F2`X#x_j
{2%'=v
for(int i=1;;i++) `;=-71Gn~
{ p[O\}MAd#
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); +7Uv|LZ~@
//Utility.log(in.readLine()); 0ijYE
sHeader=httpConnection.getHeaderFieldKey(i); %aI,K0\
if(sHeader!=null) }4g$aTc
{ J(G-c5&=
if(sHeader.equals("Content-Length")) y|0!sNg
{ <vE|QxpR
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); =P9Tc"2PN
break; zs(P2$
} o}&{Y2!x
} xHCdtloi?I
else B"sB0NuT/$
break; AdpJ4}|0
} 04WxV(fo'
} N%,zME
catch(IOException e){e.printStackTrace ();} 48Jt5Jz_
catch(Exception e){e.printStackTrace ();} xk
3RX9LJGX
0h~{K
Utility.log(nFileLength); (q0vql
\11+~
f|=u{6
return nFileLength; m^\&v0
} &1f3e
J)^F
9[`c"Pd
//保存下载信息（文件指针位置） Lu~E5 ,
private void write_nPos() ^9`|QF
{ joDqv,iW8
try{ `M*jrkM]x
output = new DataOutputStream(new FileOutputStream(tmpFile)); op@=0d??
output.writeInt(nStartPos.length); g${JdxR:
for(int i=0;i<nStartPos.length;i++) KYZ#.f@
{ @tJ4^<`P{
// output.writeLong(nPos); ')}itS8
output.writeLong(fileSplitterFetch.nStartPos); {+ Ibi{
output.writeLong(fileSplitterFetch.nEndPos); 0~EGrEt
} E]v]fy"
output.close(); /N({"G'
} ySB0"bl
catch(IOException e){e.printStackTrace ();} w=CzPNRHH!
catch(Exception e){e.printStackTrace ();} p>O/H1US;
} o%f:BJS
n|pdYe8\
*T#^|<.XG
//读取保存的下载信息（文件指针位置） @`#x:p:
private void read_nPos() hj&~Dn(
{ 2~4&4
try{ ::+;PRy_E
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); DSRmFxkk
int nCount = input.readInt(); d/T&J=
nStartPos = new long[nCount]; (/0dtJ
nEndPos = new long[nCount]; D^2lb"3
for(int i=0;i<nStartPos.length;i++) @}19:A<'
{ 5HsF#
nStartPos = input.readLong(); J>k 6`gw
nEndPos = input.readLong(); aNs8T`
} Fc80HK5R
input.close(); dF09_nw
} J2 /19'QE
catch(IOException e){e.printStackTrace ();} ]kXWeY<
catch(Exception e){e.printStackTrace ();} a'`?kBK7`U
} Ch3MwM5]
9=j)g
_Rb2jq(&0
private void processErrorCode(int nErrorCode) <[D>[
{ |AacV
System.err.println("Error Code : " + nErrorCode); RJUIB
} .heU Ir,
REgM
j>e RV ol
//停止文件下载 g1?9ge1
public void siteStop() SB08-G2
{ o<iU;15
bStop = true; ;c)( 'k<
for(int i=0;i<nStartPos.length;i++) P;@j
fileSplitterFetch.splitterStop(); G@`ZDn
L&y"oAp<
&PH:J*?C}
} DRR)mQBb
} !zm;C@}ln
//负责部分文件的抓取 4;W{#jk
**FileSplitterFetch.java 'e*w8h
*/ Cl9rJ oT
package NetFox; ^-Ygh[x
~ +>ehU
P[-do
import java.io.*; ?pfr^ !@$
import java.net.*; _9t1aP5
;2\6U;
W8$0y2
public class FileSplitterFetch extends Thread { "/RMIS K[;
JBLUX,
<&3aP}
String sURL; //File URL 7i{(,:
long nStartPos; //File Snippet Start Position P$0c{B4I
long nEndPos; //File Snippet End Position 2IE\O8b
int nThreadID; //Thread's ID {l5fKVb\C
boolean bDownOver = false; //Downing is over G'p322Bu
boolean bStop = false; //Stop identical Y)]C.V,~
FileAccessI fileAccessI = null; //File Access interface xp'Q>%v
.4U*.Rf
n}[S
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException <K<#)mcv
{ +-(,'slov
this.sURL = sURL; JKfJ%yy |
this.nStartPos = nStart; !H)-
this.nEndPos = nEnd; enZZ+|h
nThreadID = id; cV0CI&
fileAccessI = new FileAccessI(sName,nStartPos);//定位 b}ya9tCl;
} >p@b$po
?>7-a~*A@
/5/gnpC
public void run() j*gJP !
{ kE.4 #
while(nStartPos < nEndPos && !bStop) IQ_s]b;z
{ );VuZsmi
T]Ai{@i
_K!.TM+9
try{ S4 Uu/EX6S
URL url = new URL(sURL); Dol{y=(3e
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); DBB&6~;?
httpConnection.setRequestProperty("User-Agent","NetFox"); M2|h.+[Q
String sProperty = "bytes="+nStartPos+"-"; E/a2b(,Tg
httpConnection.setRequestProperty("RANGE",sProperty); pc0{
Utility.log(sProperty); MjQju@
\.O&-oi
Wh| T3&
InputStream input = httpConnection.getInputStream(); wiZ
//logResponseHead(httpConnection); S} OO)
hL6;n*S=
~gff{Nzk
byte[] b = new byte[1024]; fV5$[CL1
int nRead; %+Ze$c}X
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) Iq4B%xo6G
{ bTrusSAl
nStartPos += fileAccessI.write(b,0,nRead); ,0,FzxX0!
//if(nThreadID == 1) dH;2OWM
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); =WW5H\?
} $.,B2}'
>@Ht*h{~
qf\W,SM
Utility.log("Thread " + nThreadID + " is over!"); ?.%dQ0
bDownOver = true; SU4i'o
//nPos = fileAccessI.write (b,0,nRead); ]#^v754X^T
} tx>7?e8E
catch(Exception e){e.printStackTrace ();} E5)0YYjHZ
} 9l&q}
} 6V]m0{:E
:,aY|2si
Sk>=C0f:
//打印回应的头信息 !|xB>d q?
public void logResponseHead(HttpURLConnection con) t~j6wsx;
{ \q1tT!]
for(int i=1;;i++) $1|E(d1
{ Vez8~r3
String header=con.getHeaderFieldKey(i); N;'c4=M~(
if(header!=null) jK]1X8
//responseHeaders.put(header,httpConnection.getHeaderField(header)); 2{63:f1c`'
Utility.log(header+" : "+con.getHeaderField(header)); z5]6"v-
else 8I/3T
break; +71<B>L
} 0LH6G[
} wCNn/%C
I ]ZZN6"
*YeQCt-l
public void splitterStop() jBYvOy*$Q
{ 15Mtlb
bStop = true; eN,9N]K
} ga%\n!S
O8$~dzf,2
w=WF$)ZU
} 6d6cZGS[:
)wM%Ul<s
McasnjC
/* b-VygLN
**FileAccess.java +|obU9M
*//文件访问(定位，写) VZWo.Br'W
package NetFox; * &:_Vgu
import java.io.*; [5?Dov^j3
MVzuE}
uW!XzX['
public class FileAccessI implements Serializable{ zFExYYd
lxL.ztL
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 ^%9oeT{
RandomAccessFile oSavedFile; /Rq\Mgb
long nPos; .5G`Y
jjj<B'zt
;(/go\m tB
public FileAccessI() throws IOException N,Ma\D+^t
{ ErK1j
this("",0); f_S$CFa@
} 6Bjo9,L
}OAU5P!rp
hbx4[Pf
public FileAccessI(String sName,long nPos) throws IOException Cj8&wz}ez
{ `w:kY9
oSavedFile = new RandomAccessFile(sName,"rw"); 9hIKx:XCg
this.nPos = nPos; Ldz]FB|
oSavedFile.seek(nPos); CLaQE{
} fasWb&~z
r$={_M$
JFm@jc
public synchronized int write(byte[] b,int nStart,int nLen) c}qpmWF
{ ZDFq=)0C
int n = -1; Qi`3$<W>
try{ [Xu8~c X
oSavedFile.write(b,nStart,nLen); <@.e.H
n = nLen; gA(npsUHI
} [_)`G*X(N
catch(IOException e) 6AAvsu:
{ XMI*obS'z
e.printStackTrace (); ]LC4rS
} hI86WP9*
|})s0TU
lrv-[}}
return n; 0#J~@1Gf
} 1z6aMd6.
Z\IM~-
y 9]d{:9
} lw9jk`7^
ZxnPSA@%
'lZlfS:Z8
/* ES+CAwqf
**SiteInfoBean.java pKc!sdC
*/ kBR=a%kG
package NetFox; _k2R^/9Ct%
<J;O$S
XZ |L D#
public class SiteInfoBean { `}),wBq
zVS{X=u
g9pKoi|\E
private String sSiteURL; //Site's URL 6m;>R%S_
private String sFilePath; //Saved File's Path *m"9F'(Sd
private String sFileName; //Saved File's Name 9xK>fM&u
private int nSplitter; //Count of Splited Downloading File @n)?=[p
/ 3N2?zS{
{S=<(A@
public SiteInfoBean() uQO5GDuK>
{//nSplitter的缺省值为5 5qnei\~
//default value of nSplitter is 5 }gv'r ";
this("","","",5); 9!n:hhJM
} 1$T`j2s
0vqH-)}
y$R8J:5f
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) $vXY"-k
{ |D)CAQn,
sSiteURL= sURL; $\P/ %eP
sFilePath = sPath; %HG+|)b
sFileName = sName; 7He"IJ
this.nSplitter = nSpiltter; FAnz0p+t
ED>7
5<(* +mP`
} w PR Ns9^
LLTr+@lj
QPf\lN/$4d
public String getSSiteURL() _;PQt" ]
{ !}*vM@)1
return sSiteURL; ;I*t5{
} kc2B_+Y1
t08U9`w
MM32\}Y6
public void setSSiteURL(String value) M$EF 8
{ UmVn:a
sSiteURL = value; <9pI~\@w
} IE\RP!
@H?OHpJ"`
D=a*Xu2zq
public String getSFilePath() l\{Qnb(
{ *,X)tZ6VX
return sFilePath; }SSg>.48w
} ~},H+A!?
6n2RTH
R9A:"sJ
public void setSFilePath(String value) 2@a'n@-
{ KJT N"hF
sFilePath = value; DIGw4g4Kt
} \2/X$x<?X
_ooHB>sH
t[!,puZc#
public String getSFileName() M#^q <K %
{ D/=05E%[81
return sFileName; k$%{w\?Jf
} #eKKH]J/
e2=}qE7
jj&G[-"bv
public void setSFileName(String value) p_Xfj2E4c
{ 85# 3|5n
sFileName = value; ODu/B'*
} oX)a6FXK>
.'M.yE~5J
zKP[]S-
public int getNSplitter() mfZbo#KS#v
{ |iJz[%
return nSplitter; .K~V DUu
} On);SN'
O])vR<[
vltE2mb
public void setNSplitter(int nCount) zk$h71<{.
{ {($mLfC4
nSplitter = nCount; 2+pw%#fe
} w31O~Ve
} ^kNVQJiZyG
=Jl\^u%H(x
TgV-U
/* ?5">50
**Utility.java \_.'/<aQ
*/ mL1ZSX o!
package NetFox; 1R-0b{w[
1W*Qc_5 v1
?:vg`m!*
public class Utility { wOL%otEf
53uptQ{
T|\sN*}\8J
public Utility() 1N _"Mm{
{ n2*Ua/J-8
xy>$^/[$
/w dvm4
} &S.p%Qe"
;,Vdj[W$>
//线程睡眠 _RcEfT
public static void sleep(int nSecond) * g+v*q X
{ wa[J\lW
try{ v0WB.`rO
Thread.sleep(nSecond); EM<W+YU
} u^C\aujg
catch(Exception e) K'8o'S_bF
{ R5MN;xG^
e.printStackTrace (); Usht\<{
} hK4ww"-
} =:T"naY(
P `<TO
//日志 u@Gum|_=N
public static void log(String sMsg) ?}^ y6
{ 9i#,V@
System.err.println(sMsg); T\zn&6
} ~xam ;]2
uF%N`e^S
Nc6y]eGz
public static void log(int sMsg) *C)m#[#:u
{ or ~@!
System.err.println(sMsg); 7g8\q@',
} SN[yC
} $hJ 4=F
.nr%c*JUp
x?6^EB|@
/* !K_<7iExI\
**TestMethod.java :1'1n
*/ hBZh0xy
package NetFox; zGO_S\
4cm~oZ
:'t"kS
public class TestMethod { \py&v5J)s!
N<(rP1)`v
]%7m+-h@
public TestMethod() Yo5ged]i
{ ///xx/weblogic60b2_win.exe N+R{&v7=F%
try{ =*4^Dtp
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); |L;Hd.l7^*
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); 6EWCJ%_
SiteFileFetch fileFetch = new SiteFileFetch(bean); 9[E/^
fileFetch.start(); WFug-#;e
} V!e`P
catch(Exception e){e.printStackTrace ();} DS|x*w'I
7}=MVp] )S
/$8& r
} UQ e1rf
Nde1`W]:
' z^v}~
public static void main(String[] args) _Axw$oYS
{ %AgCE"!
new TestMethod(); 5=poe@1g
} `EP-Qlm
} N:^4OnVR
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