http断点续传简单实现（java)

亚文隆

级别: 经院学前班

发帖: 8

铜板: 1641

人品值: 95

贡献值: 0

交易币: 0

好评度: 8

信誉值: 0

金币: 0

所在楼道

只看楼主更多操作楼层直达

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)); A4?_0:<
} &~Q ?k
for(int i=0;i<nEndPos.length-1;i++) >:`Y]6z
{ Q=9S?p M
nEndPos = nStartPos[i+1]; UmU=3et<Wj
} y*6r&989
nEndPos[nEndPos.length-1] = nFileLength; :LFwJ
} yXw xq(32
} BI=Ie?
mlgdwM
\?fl%r2
//启动子线程 m-a_<xo
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; ?^&!/,
for(int i=0;i<nStartPos.length;i++) ;r[=q u\
{ xTM&SVNbL_
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), B%9[
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), :OBggb#?!
nStartPos,nEndPos,i); $hO8 S=
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); xZmKKKd0*
fileSplitterFetch.start(); /BVNJNhz
} [:!#F7O-
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), Bd"7F{H
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); FO}4~_W{
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", zq]V6.]J
nEndPos = " + nFileLength); b\?#O}
// fileSplitterFetch[nPos.length-1].start(); 3<msiCP
N[ArwV2O
v.v3HB8p
//等待子线程结束 7w{`f)~
//int count = 0; wy_TFV
//是否结束while循环 U'.>wjO
boolean breakWhile = false; M)EUR0>8
9&'Mb[C`"
J\
while(!bStop) Ye!=
{ YKl!M/
write_nPos(); ,^o^@SI)
Utility.sleep(500); mXF pGo5 s
breakWhile = true; ,lA J{5\#
N &p=4
Ze Shn
for(int i=0;i<nStartPos.length;i++) foE2rV/Y
{ :ykZ7X&
if(!fileSplitterFetch.bDownOver) i`8!Vm
{ kZGhE2np
breakWhile = false; /IV:JVT
break; Q:VD2<2
} ,bmTBZV
} a$t [}D2
if(breakWhile) nhXa&Nro
break; rmQGzQnun
4b3p,$BWS
<k^9l6@
//count++; WM=kr$/3
//if(count>4) x'JfRz
// siteStop(); -07(#>
} fBd +gT\S
TJsT .DWW~
9f,HjRP
System.err.println("文件下载结束！"); <)n
} Z@C D1+G
catch(Exception e){e.printStackTrace ();} /'VCJjzZ
} ocgbBE
~T4=Id
]P<&CEk
//获得文件长度 /e{Oqhf[n
public long getFileSize() ( v ~/glf
{ 4N` MY8',
int nFileLength = -1; #2HygS
try{ tg8VFH2q.z
URL url = new URL(siteInfoBean.getSSiteURL()); 1NOz $fW
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 'OX6eY5
httpConnection.setRequestProperty("User-Agent","NetFox"); S-f3rL[?
2,QkktJLo
H V
int responseCode=httpConnection.getResponseCode(); Y@.JW
if(responseCode>=400) i,yK&*>JJ
{ $V~%$
processErrorCode(responseCode); Fx3VQ'%J
return -2; //-2 represent access is error s9[v_(W
} At bqj?
dqKTF_+VhA
+Qc^A
String sHeader; p Y>yJ)
3?5 ~KxOE(
(J^ Tss
for(int i=1;;i++) o!\O)
{ A<.Q&4jb
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); #sqDZ]\B
//Utility.log(in.readLine()); M;43F*
sHeader=httpConnection.getHeaderFieldKey(i); 9I.v?Tap
if(sHeader!=null) ^~`8 - TE
{ P^h2w%6'
if(sHeader.equals("Content-Length")) Y6D=tb
{ ryn)
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); [Z5x_.k"I
break; ZA9']u%EJ
} W>DpDrO4ml
} giu~"#0/F
else U.^)|IHW
break; }lxvXVc{I
} Gg.w-&
} v"F0$c
catch(IOException e){e.printStackTrace ();} l5h9Eq
catch(Exception e){e.printStackTrace ();} s)M2Z3>+
R<U?)8g,h~
2bxT%xH:g
Utility.log(nFileLength); xwRnrWd^6
M"9 zK[cz
G8;S`-D1a,
return nFileLength; rf`Br\g8
} nL:vRJr-$
4 ^+hw;
ASYUKh,h
//保存下载信息（文件指针位置） PZ ogN
private void write_nPos() 93!a
{ X ]a>
try{ .y\HQ^j
output = new DataOutputStream(new FileOutputStream(tmpFile)); Maa.>2v<
output.writeInt(nStartPos.length); rL,)Tc|"
for(int i=0;i<nStartPos.length;i++) YwF6/JA0^
{ =6W:O
// output.writeLong(nPos); `riv`+J{s
output.writeLong(fileSplitterFetch.nStartPos); @Op8^8$`
output.writeLong(fileSplitterFetch.nEndPos); AQiP2`?
} - 5k4vx N}
output.close(); OUdeQO?
} Ch.T}%
catch(IOException e){e.printStackTrace ();} "=".ne
catch(Exception e){e.printStackTrace ();} E%;'3Qykva
} &iGl)dDr
H]!y |p
W?l .QQk
//读取保存的下载信息（文件指针位置） vfbe=)}[
private void read_nPos() K4F!?#
{ ~lF lv+,%
try{ & 9]KkY=
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); t~a$|( 9
int nCount = input.readInt(); .y0]( h
nStartPos = new long[nCount]; %zelpBu+
nEndPos = new long[nCount]; -E500F*b
for(int i=0;i<nStartPos.length;i++) ,m"ztu-
{ I+CQ,Zuf
nStartPos = input.readLong(); XeB>V.<y
nEndPos = input.readLong(); A5`7o9
} <eh(~
input.close(); EIYM0vls(
} aEk*-v#{
catch(IOException e){e.printStackTrace ();} 7IHD?pnZ
catch(Exception e){e.printStackTrace ();} NSgHO`gU8
} QhG-1P3#
>=`c [=:Z_
rgYuF,BT.
private void processErrorCode(int nErrorCode) $HXB !$d
{ 28)TXRr-
System.err.println("Error Code : " + nErrorCode); b"Mq7&cf
} #VOjnc/rW
*M|\B|A.
z8j(SI;3
//停止文件下载 &53#`WgJ
public void siteStop() <{U{pCT%
{ Fm;)7.% >
bStop = true; 9V],X=y~
for(int i=0;i<nStartPos.length;i++) J@GfO\ o
fileSplitterFetch.splitterStop(); YT5>pM-%
BH-[q9pf
0o<qEo^
} YMi(Cyja&
} }]~}DHYr
//负责部分文件的抓取 )*A,L%
**FileSplitterFetch.java '<0q"juXE
*/ q%k+x)
package NetFox; TN %"RL
bSr 'ji
r9M={jC
import java.io.*; Z M+Hb_6f
import java.net.*; {a3kn\6H0
ZmULy;{<)
`Q&]dE=
public class FileSplitterFetch extends Thread { UC1!J =f
+r0eTP=zf
VRX" @uCD
String sURL; //File URL bS<@Rd{g
long nStartPos; //File Snippet Start Position Jrk^J6aa
long nEndPos; //File Snippet End Position qp W#!Vbx
int nThreadID; //Thread's ID 2ZO'X9
boolean bDownOver = false; //Downing is over [)3 U])w/
boolean bStop = false; //Stop identical B (1,Rq[
FileAccessI fileAccessI = null; //File Access interface _onp%*
p0rwiBC=q
eCp|QSXE
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException >$mSFJz5S
{ ^)q2\YE;
this.sURL = sURL; (J*w./
this.nStartPos = nStart; UPKi/)C;
this.nEndPos = nEnd; 7rSUSra
nThreadID = id; (oXN>^-D
fileAccessI = new FileAccessI(sName,nStartPos);//定位 lk +K+Ra/
} DVhTb
;1.>"zX(
mbBRuPEa=u
public void run() R1.sq(z`
{ Uxemlp%%*
while(nStartPos < nEndPos && !bStop) 5b#6 Y
{ qP"JNswI_
X[Ek'=}
=4e=wAO(i
try{ -L9R&r#_e
URL url = new URL(sURL); 8'lhp2#h
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); <KwK tgzs
httpConnection.setRequestProperty("User-Agent","NetFox"); Uk:.2%S2
String sProperty = "bytes="+nStartPos+"-"; cU*lB!
httpConnection.setRequestProperty("RANGE",sProperty); z`/.v&<>V
Utility.log(sProperty); #Q3PzDfj
RW7oL:$dt
%?f:"
InputStream input = httpConnection.getInputStream(); $a^isd4
//logResponseHead(httpConnection); qd+[ShrhqZ
,Us2UEWNv
>J}n@MZ
byte[] b = new byte[1024]; -(w~LT$ "
int nRead; zw:C*sY
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) z"K( bw6
{ b%;59^4AjD
nStartPos += fileAccessI.write(b,0,nRead); JYd7@Msfc
//if(nThreadID == 1) }[z<iij4
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); v1r_Z($
} )_v\{N
s$Zq/l$1x
*e<Eu>fW#&
Utility.log("Thread " + nThreadID + " is over!"); fcICFReyV
bDownOver = true; 5$oewjLO
//nPos = fileAccessI.write (b,0,nRead); ^MT9n
} ChTXvkdH
catch(Exception e){e.printStackTrace ();} ,iVPcza
} ]&:b<]K3
} kV ,G,wo
h1XMx'}B
A*;?U2
//打印回应的头信息 C,r`I/;
public void logResponseHead(HttpURLConnection con) 8*yo7q&
{ NGD*ce"w
for(int i=1;;i++) Q0cY/'>4
{ x48'1&m
String header=con.getHeaderFieldKey(i); 7B(bH8
if(header!=null) `4%;qLxngP
//responseHeaders.put(header,httpConnection.getHeaderField(header)); `\jTpDV_W
Utility.log(header+" : "+con.getHeaderField(header)); h.V]fS
else YN@6}B#1
break; NLQE"\#a
} %)axGbZG;
} OB6J.dF[%
G*\abL
\CK(;J
public void splitterStop() JA)o@[lF
{ "#twY|wW
bStop = true; Cqgk
} %f(S'<DhC
JzMZB"Z?
5r4gmy>
} lRDxIuTK
YZGS-+
w(/DTQc~d
/* -@2'I++"@
**FileAccess.java fpvvV(
*//文件访问(定位，写) &xiOTkqB
package NetFox; ;cI#S%uvpn
import java.io.*; :p<kQ4
BR36}iS;V
'Y!pY]Z
public class FileAccessI implements Serializable{ A XBkJ'jd
hOPe^e"
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 l(%k6
RandomAccessFile oSavedFile; >BNw
long nPos; b]*X<,p
hr$Sa
?j/kOD0
public FileAccessI() throws IOException _BV`,`8}
{ QqtC`H\
this("",0); Hz?!BV0
} >z=Ou<,
Zx+cvQ
rH_Jh}Y
public FileAccessI(String sName,long nPos) throws IOException f.oP
{ {l2N&
oSavedFile = new RandomAccessFile(sName,"rw"); f=ac I|w
this.nPos = nPos; TMJ9~"IO
oSavedFile.seek(nPos); )N(9pnyZH
} LJGJ|P
pI7Ssvi^
X9fNGM1
public synchronized int write(byte[] b,int nStart,int nLen) ,+tPRkwA^
{ 3J%V%}mD
int n = -1; u#`+[AC`
try{ ljPq2v ]
oSavedFile.write(b,nStart,nLen); 6&89~W{
n = nLen; yl-fbYH
} iJdP>x
catch(IOException e) H9RGU~q4s[
{ jfUJ37zNZr
e.printStackTrace (); 5W+{U8\
} +UxI{,L
{A|bBg1!
=fl%8"%N&
return n; SLkuT`*
} XHsd-
}^"0T-ua
1SW4Y
} naz:A
^7uX$
Kax#OYLpg
/* G0}Dq MTi
**SiteInfoBean.java eC~jgB
*/ U98_M)-%&
package NetFox; y%4 Gp
P5xI
q IM
public class SiteInfoBean { v~"Ef_`
k6@b|
J58#$NC `'
private String sSiteURL; //Site's URL @\)fzubu
private String sFilePath; //Saved File's Path 9e~WK720=
private String sFileName; //Saved File's Name Z_FNIM0f
private int nSplitter; //Count of Splited Downloading File M>T[!*nTj
rvic%bsk
/D[dO6.
public SiteInfoBean() 2F1ZAl
{//nSplitter的缺省值为5 Y0@yD#,0~
//default value of nSplitter is 5 QY@u}&m%o
this("","","",5); '[nmFCG%m*
} "u;YI=+
7 _g+^e-"
0Uw ^FcW
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) cZ|lCy^
{ EKuSnlTXba
sSiteURL= sURL; R2 lXTW*
sFilePath = sPath; K\P!a@>1
sFileName = sName; gg[9u-
this.nSplitter = nSpiltter; :a.0hes
=_ y\Y@J
nUc;/
} ,=|4:F9
/s|{by`we4
)11W)G`w
public String getSSiteURL() QR"bYQ
{ 6NX3"i0eT
return sSiteURL; 0|XKd24BN
} b`CWp;6Y
; 0ko@ \Lq
%/T7Z;d
public void setSSiteURL(String value) ^s{hs(8%R
{ :p>hW!~
sSiteURL = value; Ma6W@S
} ]p]UTCo!'
S`iR9{+&
!>n|c$=;qk
public String getSFilePath() #Fs|f3-@
{ &[_ZXVva~
return sFilePath; P~RhUKfd
} & Kmy}q
yNa;\UF
ffE#^|
public void setSFilePath(String value) GK?4@<fY
{ .9h)bf+
sFilePath = value; *Qkc[XHqy
} t> . Fl-
3b!,D
gnLn7?
public String getSFileName() >A}0Ho
{ LA4<#KP
return sFileName; ;`(R7X *3
} [2 zt ^
8IGt4UF&?
_1|$P|$P.
public void setSFileName(String value) JA^v
{ 7I}P*%(f
sFileName = value; #BY`h~&T
} #@qN8J}R
OeElMRU"
SfB8!V|;
public int getNSplitter() m"d/b~q
{ i]o"_=C
return nSplitter; W7=V{}b+
} 2YOKM#N]
T_;]fPajjD
DlTR|(AL
public void setNSplitter(int nCount) w?LrJ37u
{ |`O7nOM
nSplitter = nCount; `rb>K
} 4(cJ^]wb^
} Z4hLdHo_
B4g8 ~f
s8<gK.atl
/* 4w$_]ke
**Utility.java (\,BxvhG=
*/ osHCg
package NetFox; 9}P"^N
^6;V}2>v}
3l4NC03I&
public class Utility { Tum_aI
g|%L"-%gJ
C#Bz>2;#
public Utility() |<qs
{ nJZ6? V
H(-4:BD?
UMMB0(0D
} `bG7"o`
@ -:]P8
//线程睡眠 9em*r9-
public static void sleep(int nSecond) ,EpH4*e
{ jqnCA<G~B-
try{ }< 5F
Thread.sleep(nSecond); {i [y9
} OB-Q /?0
catch(Exception e) zsXpA0~3s
{ ..W-76{
e.printStackTrace (); s9)8b$t]
} LM)`CELsYc
} f{&bOF v
?GT@puJS-
//日志 @T-p2#&
public static void log(String sMsg) `>lzlEhKV
{ ,0N94pKy
System.err.println(sMsg); +T{'V^
} #{J,kcxS
$_;e>*+x
1wj:aD?g
public static void log(int sMsg) If-_?wZe
{ T7*wS#z)h
System.err.println(sMsg); !#yq@2QX
} &1|?BZv
} K>/%X!RW
\2C`<h$fN
_D, ;MB&7
/* D=r))
**TestMethod.java Iah[j,]r
*/ tt_o$D~kg
package NetFox; SA"p\}"
<|B1wa:|
Q \hY7Xq'
public class TestMethod { \nqkA{;B{
p0:kz l4$
OO) ~HV4\
public TestMethod() +IFw_3$
{ ///xx/weblogic60b2_win.exe /=?x{(B>
try{ #Pk$L+C
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); N)2f7j4C&
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); Z.PBu|Kx
SiteFileFetch fileFetch = new SiteFileFetch(bean); *fMpZ+;[m
fileFetch.start(); AyKMhac
} NAC_pM&B
catch(Exception e){e.printStackTrace ();} fwR_OB:$
7- d.ZG
wK_]/Q-L
} Z8O n%Mx{"
c}Z6V1]QP
&[Xu!LP
public static void main(String[] args) fV>CZ^=G
{ k?B[>aQn.0
new TestMethod(); )!bUR\
} |SZo' 6
} %r\n%$@_
点击下载更多相关资料