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)); S8[=S
} )L{ghy
for(int i=0;i<nEndPos.length-1;i++) ^DeERB
{ R0ID2:i]F
nEndPos = nStartPos[i+1]; 58\&/lYW
} XR2~Q)@
nEndPos[nEndPos.length-1] = nFileLength; TxjYrzC
} `*", <
} 6tHO!`}1
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)c n+1R
//启动子线程 (wIzat
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; N'r3`8tS
for(int i=0;i<nStartPos.length;i++) F:@70(<w%
{ [FA{x?vkf
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), *4+3ObA
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), Vtc36-\1*
nStartPos,nEndPos,i); *_a@z1
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); {"oxJ`z4
fileSplitterFetch.start(); "Ve.cP,7(
} CYYkzcc^
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), wO ?+Nh
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); |(5W86C,ju
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", kpL@P oQ/r
nEndPos = " + nFileLength); FuI73
// fileSplitterFetch[nPos.length-1].start(); *f&EoUk}F
{!6/x9>
ku$$ 1xq
//等待子线程结束 Ya>oCr}K
//int count = 0; Gj"7s8(/K|
//是否结束while循环 t!*+8Q!e
boolean breakWhile = false; 1) ta
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7K)6^r^
while(!bStop) mxb(<9O
{ g?-lk5
write_nPos(); |f~@8|MQP+
Utility.sleep(500); 3)-/`iy#
breakWhile = true; j83p)ido
I}Nd$P)>
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for(int i=0;i<nStartPos.length;i++) hX`}Q4(k
{ C<KrMRWh^
if(!fileSplitterFetch.bDownOver) (Yp+bS(PU*
{ %K(<$!
breakWhile = false; pw7[y^[Qg
break; @u==x*{|
} -@T/b$]'n
} zSo)k~&[3
if(breakWhile) Q+4Xs.#
break; T,| 1g6
_g1b{$
r.4LU
//count++; !r#?C9Sq
//if(count>4) -S3MH1TZ
// siteStop(); M\yT).>z
} Neg,qOt
!9Aaj<yxm
T&Lb<'f
System.err.println("文件下载结束！"); ^i:`ZfA#
} 8_T6_jL<
catch(Exception e){e.printStackTrace ();} !\&;h
} z9aY]lHY
K~@Mg1R
'1M7M(va
//获得文件长度 gy&[?m6M=
public long getFileSize() W5SJ^,d)J
{ |V<h=D5W
int nFileLength = -1; 035rPT7-2-
try{ <.Nx[!'~&d
URL url = new URL(siteInfoBean.getSSiteURL()); G:zua`u[
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); Me 5_4H&Sg
httpConnection.setRequestProperty("User-Agent","NetFox"); |SyMngIY
r*Yi1j/
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int responseCode=httpConnection.getResponseCode(); R {-5Etv
if(responseCode>=400) _YF%V;X
{ `FoxP
processErrorCode(responseCode); X7s `U5'l
return -2; //-2 represent access is error ^tXJj:wtS
} zbq@pj)Qu
6R=W}q4
27;ci:5
String sHeader; J~#;<e{\"
OE}*2P/M>
N^3N[lD{
for(int i=1;;i++) lsJnI|
{ !?|Th5e
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); ANgw"&&>(
//Utility.log(in.readLine()); 9W(dmde>
sHeader=httpConnection.getHeaderFieldKey(i); 1Tu *79A
if(sHeader!=null) .'Vww
{ S#+h$UVh
if(sHeader.equals("Content-Length")) *4V=z#
{ H,b5C_D29
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); 2Lx3=[ik
break; aG^4BpIP
} )I3NeKWz
} ?Wz8[u
else EVoEszR
break; TYy.jFT-
} 0{=`on;
} ,T2G~^0
catch(IOException e){e.printStackTrace ();} *8LMn
catch(Exception e){e.printStackTrace ();} 7}X[ 4("bB
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nw-I|PVTNa
Utility.log(nFileLength); P>Ez'C
ub|V\M{
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return nFileLength; 5-M&5f.
} |`cKD >
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,lyb!k8
//保存下载信息（文件指针位置） 3g >B"t
private void write_nPos() a[ex[TRKe
{ _'(,
try{ \_lod kf
output = new DataOutputStream(new FileOutputStream(tmpFile)); Rj4|Q:XG
output.writeInt(nStartPos.length); E@ESl0a;
for(int i=0;i<nStartPos.length;i++) .FLy;_f+
{ NUp<e%zB
// output.writeLong(nPos); %@u;5qD&
output.writeLong(fileSplitterFetch.nStartPos); zzyHoZJP
output.writeLong(fileSplitterFetch.nEndPos); rnF/H=I/
} 6q{HU]N+
output.close(); Bro9YP4<
} B&@?*^.
catch(IOException e){e.printStackTrace ();} g[3)P+
catch(Exception e){e.printStackTrace ();} 9^j &VmF
} _A=$oVe
~m$Y$,uH
)'~6HO8Z
//读取保存的下载信息（文件指针位置） ={z*akn,
private void read_nPos() $g sxO!G
{ B#M5}QT|2
try{ Rp5#clsy
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); |]c8jG\h
int nCount = input.readInt(); DK$s&zf
nStartPos = new long[nCount]; Qc pm!
nEndPos = new long[nCount]; R;j!}D!4
for(int i=0;i<nStartPos.length;i++) :AE&Ny4
{ |cR;{Z8?_
nStartPos = input.readLong(); ` eXaT8
nEndPos = input.readLong(); CY"/uSB
} & 9<+;*/
input.close(); }nL7T'$>
} &sU?Ok6
catch(IOException e){e.printStackTrace ();} w'UVKpG+
catch(Exception e){e.printStackTrace ();} TTKs3iTXz
} H XmS|PX
FAj)OTI2S
WS`qVL]^&
private void processErrorCode(int nErrorCode) 'L8' '(eZ^
{ }&[
System.err.println("Error Code : " + nErrorCode); F~P%AjAx'
} w$Rro)?}7
sashzVwJ-=
NB8/g0:=n&
//停止文件下载 1A\OC
public void siteStop() H(Z88.OM
{ F 9@h|#an
bStop = true; m_)FC-/pSl
for(int i=0;i<nStartPos.length;i++) !s&NT @ S
fileSplitterFetch.splitterStop(); yI"6Da6|y
;9c<K
&MCbYph,
} P3=W|81e
} ,=#F//
//负责部分文件的抓取 ayfFVTy1d
**FileSplitterFetch.java o<|P9#(U"
*/ }3OKC2K~
package NetFox; MZT23[+
6Q${U7%7
;u>DNG|.
import java.io.*; `nZ)>
import java.net.*; RE/~#k@a
1fZ(l"
e=+?K5q{P(
public class FileSplitterFetch extends Thread { 7*?}:
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String sURL; //File URL iLkZ"X.'|1
long nStartPos; //File Snippet Start Position %|^fi8!:|
long nEndPos; //File Snippet End Position %'X[^W
int nThreadID; //Thread's ID id1s3b;
boolean bDownOver = false; //Downing is over ,&R/4:I
boolean bStop = false; //Stop identical mD^jd+
FileAccessI fileAccessI = null; //File Access interface [rSR:V?"a
[D<1CF
z}MP)|aH:
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException /K.!sQ$
{ "-+\R}q$
this.sURL = sURL; Bi @2
this.nStartPos = nStart; %>g3~yl
this.nEndPos = nEnd; `#;e)1
nThreadID = id; 2(#7[mgPI
fileAccessI = new FileAccessI(sName,nStartPos);//定位 .~l=zu
} Yi$vg
61)-cVC
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public void run() U G~ba
{ +,#$:fs u
while(nStartPos < nEndPos && !bStop) TzNn^ir=HX
{ $3s@}vLd
{/ BT9|LI
qLB)XnQ
try{ Ht&:-F+dm
URL url = new URL(sURL); AMyIAZnYq)
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); B>0].CK`
httpConnection.setRequestProperty("User-Agent","NetFox"); V{:A3C41
String sProperty = "bytes="+nStartPos+"-"; USM4r!x
httpConnection.setRequestProperty("RANGE",sProperty); xUa{1!Y8
Utility.log(sProperty); YLiSbLz1
M!REygyx
IVAmV!.z
InputStream input = httpConnection.getInputStream(); =AEBeiz
//logResponseHead(httpConnection); pQtJc*[!
wfq7ob4^
G}ob<`o|"
byte[] b = new byte[1024]; H\0~#(z?.
int nRead; @CZT
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) B4i!/@0s
{ g.zEn/SM
nStartPos += fileAccessI.write(b,0,nRead); yL2o}ZbS
//if(nThreadID == 1) F)'.g d
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 0a-0Y&lQm
} y"H*%]
\uza=e
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Utility.log("Thread " + nThreadID + " is over!"); *fn*h[pV&
bDownOver = true; Ljx(\Cm
//nPos = fileAccessI.write (b,0,nRead); d ysC4DS
} 'U\<IL#U
catch(Exception e){e.printStackTrace ();} &QGdLXOn
} b"vv>Q~U
} V;:jZpG
P8*=Ls+-F
l%1!a
//打印回应的头信息 woD>!r>)
public void logResponseHead(HttpURLConnection con) j ~1B|,H
{ Zf65`K3
for(int i=1;;i++) D0%Ug>
{ (K)]qNH
String header=con.getHeaderFieldKey(i); Te<}*qvD
if(header!=null) L>SjllY
//responseHeaders.put(header,httpConnection.getHeaderField(header)); +ayos[<0#
Utility.log(header+" : "+con.getHeaderField(header)); @AIaC-,~]
else lna}@]oR
break; \4-"L>
} /7t>TYip!
} o!{w"K
2M68CE
Q2F+?w;,
public void splitterStop() o'f?YZ$.
{ {:]9Q Tq
bStop = true; e=.njMqW5
} Od5JG .]
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AigS!-
} S/ODqL|
nysUZB
OVhE??#
/* 9/ibWa\.
**FileAccess.java \8?Tdx=
*//文件访问(定位，写) a6WI170^1
package NetFox; /iJ4{p
import java.io.*; c%'RR?Tl
%|oJ>+
:QB<?HaS'
public class FileAccessI implements Serializable{ g'V>_u#(
-1UD0(
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 D-4f >
RandomAccessFile oSavedFile; 7zSLAHW
long nPos; or';A'k
i5K[>5
F=a<~EpZ
public FileAccessI() throws IOException }A7j/uy}s
{ iTAx=SG
this("",0); sSi6wO$
} Ft;^g3N
f'VX Y-
i-6F:\;
public FileAccessI(String sName,long nPos) throws IOException qCqFy#Ms\
{ |(q9"
oSavedFile = new RandomAccessFile(sName,"rw"); 0^RXGN
this.nPos = nPos; zBk'{[y9L
oSavedFile.seek(nPos); %Cv D-![0
} !`M|C?b
` M3w]qJ<}
zN:K%AiGxe
public synchronized int write(byte[] b,int nStart,int nLen) f^"N!f a
{ LkK~%tY
int n = -1; Gq }U|Z
try{ =aoMii
oSavedFile.write(b,nStart,nLen); viMzR(JU
n = nLen; HFaj-~b
} "huFA|`
catch(IOException e) dK2p7xo
{ 4*cU<
e.printStackTrace (); #[`:'e
} vWf; 'j
< VSA
jhg;%+KB
return n; ?)1{)Erf8x
} GP:77)b5
R5 9S@MsuD
30.@g[~
} By9*1H2R
*UmI]E{g3(
J_v$YwE
/* FWHNj.r
**SiteInfoBean.java A3S<..g2
*/ ~;&m*2 |V
package NetFox; @Q/-s9b
82QGS$0V
/(BMG/Tb
public class SiteInfoBean { q~vDz]\G
Lg*B>=
CS=qj-(
private String sSiteURL; //Site's URL }=8B*
private String sFilePath; //Saved File's Path +[tE^`-F
private String sFileName; //Saved File's Name v>-VlQ
private int nSplitter; //Count of Splited Downloading File dnb)/
A' /KUi
cdZ~2vk
public SiteInfoBean() ##V5-ZG{:
{//nSplitter的缺省值为5 tP2qK_\e=
//default value of nSplitter is 5 YA +E\
this("","","",5); h}cy D7Wn
} N0=ac5
?hWwj6i&
9=V:&.L
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) HOE_S!N
{ a8i]]1Blz
sSiteURL= sURL; ulkJR-""&
sFilePath = sPath; z3K6%rb-
sFileName = sName; .D:Z{|.1
this.nSplitter = nSpiltter; Z<SLc,]^
JA'h4AXk
%JHGiCv|
} R%qGPO5Z\c
d\61;C
},>pDeX^P
public String getSSiteURL() Qkd<sxL
{ qLT>Mz)$%
return sSiteURL; 3`ELKq
} v{jQek4
bV$)!]V
G1"zElug
public void setSSiteURL(String value) krC{ed
{ Y<Xz wro0
sSiteURL = value; r]l!WRn
} W81E!RyP`
OZTPOz.
l#H#+*F
public String getSFilePath() ]) rrG/3
{ l-s!A(l
return sFilePath; %_{tzXim
} hDcEGU_
vpld*TL*
"(3BvMA&!9
public void setSFilePath(String value) 8-_QFgY
{ _&j}<K$-(
sFilePath = value; _`_%Y(Xat
} w - Pk7I
'eJ+JM<0%
bD[!/'4eJ
public String getSFileName() M5*{
{ I{lT>go
return sFileName; ,>:;#2+og
} MwR0@S}*
T:IW%?M
ywb4LKD
public void setSFileName(String value) ae*Mf7
{ z[cyA.
sFileName = value; f~dd3m('
} @Q^P{
>9q&PEc
%ix)8+Eb
public int getNSplitter() DVK)2La
{ C#t'Y*
return nSplitter; 9XRZ$j}L
} N^pJS6cJkl
<oWB0%
DWID$w
public void setNSplitter(int nCount) &/uu)v
{ &%s8L\?
nSplitter = nCount; '{J&M|<A
} <YOLxR
} AjT%]9 V?
Xy@7y[s]
1 29q`u;
/* =9z[[dQ|L
**Utility.java e#Z$o($t
*/ ( @3\`\X
package NetFox; mdq;R*`
r; xLP
{.De4]ANh
public class Utility { CMCO}#
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e?Ho a$k
public Utility() 98WZ){+,m
{ RheRe
@~#Ym1{W
ooV3gj4
} rN%F) q#
7hi"6,
//线程睡眠 aS pWsT
public static void sleep(int nSecond) #F*1V(!
{ ,daKC
try{ ^~$)F_`"
Thread.sleep(nSecond); RgGyoZ
} _x?uU
catch(Exception e) ObE,$_ k
{ ;+tpvnV;]
e.printStackTrace (); GD:4"$)[o
} >9f%@uSM$3
} }j^\(2
>TP7 }u|
//日志 CXO2N1~(J
public static void log(String sMsg) S=nP[s
{ ecgtUb8K
System.err.println(sMsg); _^'I
} ]_8qn'7
i@B[ eta
~>:Z6Le@
public static void log(int sMsg) h?f>X"*|(
{ MUA%^)#u4Q
System.err.println(sMsg); gt ";2,;X
} ylB7*>[
} m@Qt.4m%g
X5`AGyX
r.T<j.\
/* +]|Z%;im
**TestMethod.java :Pg}Zz<
*/ n f.wCtf].
package NetFox; 4<?8M vF
;i"*Ll>Q)
X5khCLHi
public class TestMethod { }#qGqY*@LK
V%_4%
m1IKVa7-\}
public TestMethod() mCWhUBghR
{ ///xx/weblogic60b2_win.exe BA:yQ
try{ 2PeR
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); E^rbcGJ
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); =Me5ftw
SiteFileFetch fileFetch = new SiteFileFetch(bean); sj8~?O
fileFetch.start(); Ht-t1q
} [b/k3&O'
catch(Exception e){e.printStackTrace ();} tBm_YP[
i:cXwQG}B
Pf$pt
} r 3M1e+'fc
tU^kQR!
+4,2<\fX
public static void main(String[] args) 5hbJOo0BZ
{ *5wu
new TestMethod(); e{A9r@p!
} +MB!B9M@
} b-Z4 Jo G
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