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)); e{X6i^% m_
} Dfps gY)/?
for(int i=0;i<nEndPos.length-1;i++) YY&l?*M<
{ S-7'it!1
nEndPos = nStartPos[i+1]; B=>RH!&
} CbPuoOl
nEndPos[nEndPos.length-1] = nFileLength; Oy<5>2^P
} "z0zpHXek
} OkCQ?]
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//启动子线程 5Xl/L
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; NE/m-ILw
for(int i=0;i<nStartPos.length;i++) oq4}3bQ
{ 0O\SU"bP
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), ZDD..j
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), WVmq% ,7
nStartPos,nEndPos,i); ddfs8\
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); u)ev{)$TM
fileSplitterFetch.start(); )I^2k4Cg"
} Nc:({@I
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), ({-GOw46
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); n6*En7IVh
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", !L;\cl
nEndPos = " + nFileLength); Aub]IO~
// fileSplitterFetch[nPos.length-1].start(); -b9;5eS!
$we]91(::
{/X4(;~0
//等待子线程结束 4q'B<7{Q
//int count = 0; :N<.?%Kf
//是否结束while循环 s:2|c]wQ#R
boolean breakWhile = false; ~6pr0uyO`
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z-@=+4~
while(!bStop) 3I!?e!y3(
{ -29gL_dk.
write_nPos(); 2u"7T_"2D
Utility.sleep(500); =/u%c!
breakWhile = true; pG34Qw
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for(int i=0;i<nStartPos.length;i++) t~e<z81p
{ ~_9n.C
if(!fileSplitterFetch.bDownOver) b{d4xU8'
{ n:0}utU4
breakWhile = false; bn(`O1r[(
break; 'Q =7/dY3I
} 2+cNo9f
} ik"sq}u_]E
if(breakWhile) l"q1?kaVg
break; /erN;Oo%<
ed!:/+3e/
zF@o2<cD@
//count++; <W`#gn0b6
//if(count>4) 4\pWB90V
// siteStop(); j ,)P9V
} DbZ0e5
7R3fqU.Rq
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System.err.println("文件下载结束！"); osOVg0Gyj
} +B'8|5tPX
catch(Exception e){e.printStackTrace ();} Z<#hS=eY
} 4<lQwV6=
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//获得文件长度 [L6w1b,
public long getFileSize() kWlAY%
{ /Y&02L%\3s
int nFileLength = -1; *d(SI<j
try{ @v}B6j b;
URL url = new URL(siteInfoBean.getSSiteURL()); LuR,f"%2
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); )jCo%P/
httpConnection.setRequestProperty("User-Agent","NetFox"); d'*]ns
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E"%2)
int responseCode=httpConnection.getResponseCode(); sowd`I~
if(responseCode>=400) 4J|t?]ij|E
{ YC=S5;
processErrorCode(responseCode); T# lP!c
return -2; //-2 represent access is error WKpA|
} !mRx$ %ul
.}k(L4T|=
nx:KoB"ny
String sHeader; FP#FB$eP
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for(int i=1;;i++) e8h,,:l3j
{ '~ 4pl0TWc
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); T"T;`y@(
//Utility.log(in.readLine()); DY{cQb
sHeader=httpConnection.getHeaderFieldKey(i); e,k2vp!<&
if(sHeader!=null) /<&h@$NHH4
{ ?\/qeGW6G
if(sHeader.equals("Content-Length")) 1^dJg8
{ _TUt9}
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); $&Kq*m 0g
break; >r)X:K+I
} <&pKc6+{
} |!H?+Jj:
else mPPk)qy
break; =s}Xy_+:
} joa5|t!D9
} QM5 .f+/
catch(IOException e){e.printStackTrace ();} 85|fyX
catch(Exception e){e.printStackTrace ();} V8-h%|$p3W
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#hL*rbpT
Utility.log(nFileLength); j2M+]Zp.
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return nFileLength; g,]@4|
} "PH6e bm
-6=<#9R
)9=(|Lp
//保存下载信息（文件指针位置） `@`1pOb
private void write_nPos() RGD]8mw
{ 64j|}wJ$
try{ hzY[ G:
output = new DataOutputStream(new FileOutputStream(tmpFile)); | A:@&|
output.writeInt(nStartPos.length); _7kM]">j
for(int i=0;i<nStartPos.length;i++) 6<Hu8$G|
{ /^#G0f*N
// output.writeLong(nPos); |%D%0TR&Q
output.writeLong(fileSplitterFetch.nStartPos); Zg:gY"^
output.writeLong(fileSplitterFetch.nEndPos); !EF(*~r!9L
} )F pJ1
output.close(); >0Ev#cX4
} m@rSz
catch(IOException e){e.printStackTrace ();} Ep~wWQh
catch(Exception e){e.printStackTrace ();} ~2uh'e3
} U5/qf8)yO
>qn/<??
7ODaX.t->
//读取保存的下载信息（文件指针位置） -DO&_`kn
private void read_nPos() wH"kk4^
{ XTqm]
try{ RbQ <m!A
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); LH]CUfUrUE
int nCount = input.readInt(); 49 }{R/:
nStartPos = new long[nCount]; DFe;4BdC
nEndPos = new long[nCount]; TSL9ax4j
for(int i=0;i<nStartPos.length;i++) 7\/5r.
{ 4p)e}W*
nStartPos = input.readLong(); $E(XjuS
nEndPos = input.readLong(); _qWC4NMF(
} 9 1P4:6
input.close(); R9r+kj_
} AxCI 0
catch(IOException e){e.printStackTrace ();} PI|`vC|yy&
catch(Exception e){e.printStackTrace ();} VY'Q|[
} ; !$m1
dEp/dd~(&
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private void processErrorCode(int nErrorCode) =qoRS0Qa
{ 2H[)1|]l
System.err.println("Error Code : " + nErrorCode); ~U}Mv{y
} noA-)
.Gb+\E{M
X;fy\HaU
//停止文件下载 45}v^|Je\
public void siteStop() s&*yk p
{ BIWD/|LQ
bStop = true; &1)xoZ'\
for(int i=0;i<nStartPos.length;i++) *M~.3$NN
fileSplitterFetch.splitterStop(); FWPW/oC
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<>4!XPo%J
} ;R[&pDx
} zp=!8Av
//负责部分文件的抓取 }++5_Z_
**FileSplitterFetch.java h8^i\j
*/ d,'!.#e
package NetFox; ]1fZupM^6
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import java.io.*; pbB2wt
import java.net.*; \~"#ld(x7
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[}""@?
public class FileSplitterFetch extends Thread { ,5-Zb3\
?ow'^X-
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String sURL; //File URL ZTf_#eS$
long nStartPos; //File Snippet Start Position 'M%5v'$y
long nEndPos; //File Snippet End Position dl[ob,aCK
int nThreadID; //Thread's ID FOG+[v
boolean bDownOver = false; //Downing is over Z|dZc wo
boolean bStop = false; //Stop identical <sB45sNbU`
FileAccessI fileAccessI = null; //File Access interface Y1+lk^
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public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException ,VsCRp
{ 13kb~'+&r
this.sURL = sURL; z))[Lg
this.nStartPos = nStart; 7uNI
this.nEndPos = nEnd; be#"517
nThreadID = id; ^!Jm/-
fileAccessI = new FileAccessI(sName,nStartPos);//定位 <Pt\)"JA
} qM !q,Q
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*)D*iU&
public void run() kP@OIhRe
{ OSIp
while(nStartPos < nEndPos && !bStop) R0d|j#vP
{ S IK{GWX
M=`Se&-M
O;?~#E<6w
try{ Bcon4
URL url = new URL(sURL); I>Yp=R
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 6l7a9IJ
httpConnection.setRequestProperty("User-Agent","NetFox"); bLF0MVLM
String sProperty = "bytes="+nStartPos+"-"; v[3sg2.
httpConnection.setRequestProperty("RANGE",sProperty); d`7] reh
Utility.log(sProperty); 8E%*o
Vp^sER
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InputStream input = httpConnection.getInputStream(); 5&@U T
//logResponseHead(httpConnection); +0 |0X {v
}TL"v|ny6;
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byte[] b = new byte[1024]; hI{Yg$H1
int nRead; UQPE)G
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) Oh4WYDyT
{ F[Sat;Sll
nStartPos += fileAccessI.write(b,0,nRead); 7Z3qaXPH
//if(nThreadID == 1) :|3C-+[
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); c?",kzo
} }TvAjLIS6
QLG,r^
hDMp^^$
Utility.log("Thread " + nThreadID + " is over!"); }>U03aa!
bDownOver = true; "iGc'?/+
//nPos = fileAccessI.write (b,0,nRead); -h`0v
} .&.CbE8K[
catch(Exception e){e.printStackTrace ();} >E=a~ O
} O8o18m8UH
} &W!@3O{~.
a<.@+sj{
iNSJOS
//打印回应的头信息 0eP~F2<bC
public void logResponseHead(HttpURLConnection con) ev >9P
{ B ;$8<
for(int i=1;;i++) &,7(Wab
{ xII!2.
String header=con.getHeaderFieldKey(i); ]XyJ7esg
if(header!=null) So`"z[5
//responseHeaders.put(header,httpConnection.getHeaderField(header)); R&xd ic!
Utility.log(header+" : "+con.getHeaderField(header)); gXMkI$ab
else [?*^&[
break; mJ7kOQ-.$
} B=`!
} Yg.u8{H
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public void splitterStop() p\\q[6
{ pE,BE%
bStop = true; PX)qA=4q
} _P1-d`b0 a
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} DlI|~
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/* do7{
**FileAccess.java xE_[=7=
*//文件访问(定位，写) _Tz!~z
package NetFox; b\Ub<pE
import java.io.*; C:{'0m*jKs
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qW^l2Jff
public class FileAccessI implements Serializable{ U+ =q_ <
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//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 H(s^le:!
RandomAccessFile oSavedFile; oR)7 \;g
long nPos; WgB,,L,
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public FileAccessI() throws IOException &YNhKm@"
{ ZT#G:a
this("",0); ><qE5D[
} [bXZPIz;j
>2/zL.O
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public FileAccessI(String sName,long nPos) throws IOException jXf-+;ZQ
{ W+X zU"l
oSavedFile = new RandomAccessFile(sName,"rw"); f?6=H^_>
this.nPos = nPos; bX1ip2X lk
oSavedFile.seek(nPos); FC#Qtu~J
} 9h8G2J o
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x;Q2/YZ#
public synchronized int write(byte[] b,int nStart,int nLen) B?'ti{p A9
{ RJSgts "F
int n = -1; #Uu"olX7
try{ @gOgs
oSavedFile.write(b,nStart,nLen); VK#zmEiB
n = nLen; qxx.f58H
} }f}&|Vap
catch(IOException e) l-rnDl
{ Jo0x/+?,+
e.printStackTrace (); @ 2_&ti
} G'Y|MCKz>
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i747( ^
return n; iDsjIW\j
} 9^tyjX2
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} j3><J
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mVLGQlvVK
/* BJ5#!I%h
**SiteInfoBean.java #z.x3D@^r6
*/ 5{> cfN\q
package NetFox; m[f\I^\%8
%y q}4[S+o
:?J$ +bm}
public class SiteInfoBean { 'e@}N)IX
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private String sSiteURL; //Site's URL J98K:SAR
private String sFilePath; //Saved File's Path ?0x;L/d])
private String sFileName; //Saved File's Name OZ6%AUot
private int nSplitter; //Count of Splited Downloading File z$NLFJvy_-
tj3p71%
BG"6jQh
public SiteInfoBean() EA\~m*k
{//nSplitter的缺省值为5 809-p_)B
//default value of nSplitter is 5 kAoai|m@R
this("","","",5); R/W&~t
} q3:tZoeXV
!`gg$9
` T!O )5
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) ^RyrUb
{ ,x/j&S9!
sSiteURL= sURL; "'Q:%_;
sFilePath = sPath; ]x|sTKv2
sFileName = sName; /%)J+K)
this.nSplitter = nSpiltter; #?9oA4Q
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} @;0Ep0[
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public String getSSiteURL() seq$]
{ FD<~?-
return sSiteURL; 1gC=xMAT
} ]WG\+1x9
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}\W3a_,v)
public void setSSiteURL(String value) 7>nA;F 8_
{ !q X7
sSiteURL = value; "elh~K
} vv u((b
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=k'dbcfO$9
public String getSFilePath() mXr)lA
{ &zZSWNW
return sFilePath; ^%L$$V nG
} 3eB2=_V`
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public void setSFilePath(String value) eg3{sDv,
{ (w.B_9#
sFilePath = value; Pw")|85
} l6&R g-
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public String getSFileName() O/Fzw^
{ vn8Ez6<27
return sFileName; qRUz;M4
} 6jn<YR E-
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public void setSFileName(String value) M1^pW63
{ qAm%h\
sFileName = value; 0zd1:*KR,
} 0<Y)yNsV
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public int getNSplitter() n8?gZ` W
{ |peZ`O^~
return nSplitter; 3Ry?{m^
} lY~xoHT;[
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public void setNSplitter(int nCount) +h =lAHn&
{ 8Hhe&B
nSplitter = nCount; e0D;]
} NmeTp?)m
} A >x{\
}, ]W/
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/* DI*xf Kt
**Utility.java a`T{5*@
*/ rO-Tr
package NetFox; }p#S;JZRu+
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public class Utility { $, =n
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public Utility() 6gp3n;D
{ !_]WUQvV?
O9opX\9
mFvw s
} H}:apRb
3&}wfK]X
//线程睡眠 /_LUys/0
public static void sleep(int nSecond) ~2pctqMA
{ >iq^Ts
try{ 0s4%22
Thread.sleep(nSecond); r`" ?K]rI
} b2Ct^`|M5
catch(Exception e) kcQ |Zg
{ Jl}$)'
e.printStackTrace (); Jx'p\*
} =Y89X6
} Jk`A}
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//日志 vXyaOZ
public static void log(String sMsg) r|&qXb x
{ fx9c1h9s
System.err.println(sMsg); {dA#r>z\1
} 5:O"T
& K7+V
}lWEbQ)(!
public static void log(int sMsg) -PxA~((g5
{ 4).q+{#k
System.err.println(sMsg); BM:je(*p
} o\2#o5#
} ];IUiS1
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/* 65MR(+3
**TestMethod.java {+Eq{8m`
*/ NC0x!tJ#7
package NetFox; bGDV9su
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public class TestMethod { nE,"3X"
5?QR
]` 3;8,
public TestMethod() ji">} -
{ ///xx/weblogic60b2_win.exe h(>4%hF
try{ ^f>+5G
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); 514;!Q4K
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); aN.Phn:
SiteFileFetch fileFetch = new SiteFileFetch(bean); 3pm;?6i6
fileFetch.start(); X1$0'usS
} A`IE8@&Z'
catch(Exception e){e.printStackTrace ();} !30BZM^
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} n;4`IK|
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z$;z&X$j
public static void main(String[] args) ~g)gXPjke
{ oc>,5 x
new TestMethod(); M,:GMO:?a
} ?-J\~AXL
} w,D(zk$
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