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)); 8:)itYE
} S|v")6
for(int i=0;i<nEndPos.length-1;i++) (b>B6W\&
{ x#,nR]C
nEndPos = nStartPos[i+1]; Ob>M]udn
} hTK6N
nEndPos[nEndPos.length-1] = nFileLength; \S`|7JYW
} 8S*W+l19f
} %:hU:+G E
$mq@g
w@"l0gm+u[
//启动子线程 JN:EcVuy
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; e!JC5Al7
for(int i=0;i<nStartPos.length;i++) S67>yqha
{ 3pk`&'
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), /5 6sPl 7}
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), ,CA3Q.y>|
nStartPos,nEndPos,i); ]\Q9j7}37+
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); %+e% RZ3
fileSplitterFetch.start(); }qn@8}
} i*-L_!cc:
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), H_<hZUB
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); Ed=]RR4R
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", E{B=%ZNnm
nEndPos = " + nFileLength); |$aTJ9 Iq:
// fileSplitterFetch[nPos.length-1].start(); F1UTj"<e
#>@~3kGg
bQ6<R4
//等待子线程结束 @Ap~Wok
//int count = 0; [ bB
//是否结束while循环 Dhy@!EOS
boolean breakWhile = false; B2DWSp-8*
K\a=bA}DG
@#= ail
while(!bStop) ^J{tOxO=l
{ pz]#/Ry?
write_nPos(); Zbobi,
Utility.sleep(500); P]b *hC
breakWhile = true; 8*t8F\U#
ZAcH`r*
#Kd^t=k
for(int i=0;i<nStartPos.length;i++) fKN&0N|^R
{ [>N`)]fP
if(!fileSplitterFetch.bDownOver) "o.g}Pv
{ _yJAn\
breakWhile = false; R#0Z
break; ?YTngIa
} H^N 5yOj/
} j9G1 _
if(breakWhile) a2tRmil
break; :`w'}h7m
mFdj+ &2\
eH9Ofhsry
//count++; e;ej/)no`
//if(count>4) ="*:H)
// siteStop(); , e6}p
} ollk {N
sq~9 l|F
vOKWi:-U
System.err.println("文件下载结束！"); Ug1n4X3FKn
} lE@ V>%b
catch(Exception e){e.printStackTrace ();} d}`Z| ex
} 8Q2qroT
':jsCeSB
@CJ`T&
//获得文件长度 edv&!
public long getFileSize() V`/D!8>
{ FhkS"y
int nFileLength = -1; 2y0J~P!I
try{ ,m)k;co^
URL url = new URL(siteInfoBean.getSSiteURL()); !QTfQ69Y0
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); ;@R=CQ6
httpConnection.setRequestProperty("User-Agent","NetFox"); 2GRdfX
]s))O6^f
l,n V*Z
int responseCode=httpConnection.getResponseCode(); bXw!fYm&
if(responseCode>=400) [~[)C]-=
{ RZg8y+jM
processErrorCode(responseCode); 5!pof\/a
return -2; //-2 represent access is error NEb M>1>^
} [G/ti&Od^
XzBnj7E
,4&?`Q
String sHeader; <@puWm[p
QxaW x
{hmC=j
for(int i=1;;i++) [_pw|BGp
{ MY]<^/Q
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); 6?C|pO
//Utility.log(in.readLine()); ?mCino
sHeader=httpConnection.getHeaderFieldKey(i); X?8EPCk
if(sHeader!=null) qij<XNZU"&
{ I\DH
if(sHeader.equals("Content-Length")) XFiP8aX<
{ &=-ZNWNo
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); qlJzXq{|`
break; (WISf}[l;
} z9B""ws
} [$<\*d/
else ..5rW0lr
break; (&)PlIi7
} 8wXnc%
} WX9ABh&5
catch(IOException e){e.printStackTrace ();} -xXz}2S4
catch(Exception e){e.printStackTrace ();} :47bf<w|Y
&# ?2zbZ
Z@G[\"
Utility.log(nFileLength); TJY [s-
2`?58&
ip`oL_c
return nFileLength; jrl'?`O
} y|7sh
qZS]eQW.
@3Lh/&
//保存下载信息（文件指针位置） Duu)8ru
private void write_nPos() &P@dx=6d
{ Q,f~7IVX
try{ b-+~D9U<
output = new DataOutputStream(new FileOutputStream(tmpFile)); Pd"=&Az|
output.writeInt(nStartPos.length); z3bRV{{YqN
for(int i=0;i<nStartPos.length;i++) nN]GO}
{ 1j!LK-
// output.writeLong(nPos); w I7iE4\vz
output.writeLong(fileSplitterFetch.nStartPos); 1_of;=9V
output.writeLong(fileSplitterFetch.nEndPos); ;tZ;C(;<
} k"z ~>
output.close(); s)L\D$;+O
} t{ R\\j
catch(IOException e){e.printStackTrace ();} nsM=n}$5x
catch(Exception e){e.printStackTrace ();} iiw\
} bl8EzO
0,z3A>C
dx&!RK+
//读取保存的下载信息（文件指针位置） P"%QFt,
private void read_nPos() =sYUzYm
{ `Q@w*ta)
try{ @F-InfB8.
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); Vx<`6uv
int nCount = input.readInt(); XB.xIApmy
nStartPos = new long[nCount]; WEnI[JGe
nEndPos = new long[nCount]; {PTB]D'
for(int i=0;i<nStartPos.length;i++) FoNkISzW
{ ~v$1@DQ}
nStartPos = input.readLong(); ,Hzz:ce
nEndPos = input.readLong(); 2lc
} L/Ytkag
input.close(); RnaxRnXVR
} d5z=fH9
catch(IOException e){e.printStackTrace ();} <?>1eU%
catch(Exception e){e.printStackTrace ();} (\8~W*ej"
} RXD*;B$v
X>la!}sV
p|gzU$FWbk
private void processErrorCode(int nErrorCode) :Rftn6!
{ J\@W+/#dF
System.err.println("Error Code : " + nErrorCode); !2o1c
} [qL{w&R
i!a.6Gq
)/y7Fh
//停止文件下载 3i;sB
public void siteStop() .DX-biX,
{ x@)G@'vV|
bStop = true; F{*h~7D-|
for(int i=0;i<nStartPos.length;i++) s;ivoGe}
fileSplitterFetch.splitterStop(); 6L!/#d0
\2c3Nsra
x_+-TC4IXn
} k',#T932x1
} Ov-Y.+L:
//负责部分文件的抓取 Hh1]\4D,4
**FileSplitterFetch.java ixY[ HDPq
*/ /=(PMoZu
package NetFox; v:1DNR4
3-PqUJT$
CiNOGSlDj
import java.io.*; 2bnYYQ14:
import java.net.*; 81}JX
(B^rW,V[R
M/mm2?4
public class FileSplitterFetch extends Thread { 7@1GSO:Yf
]i:_^z)R
[2P6XoI#
String sURL; //File URL N*`qsv0
long nStartPos; //File Snippet Start Position H,3WdSL`K
long nEndPos; //File Snippet End Position K0usBA
int nThreadID; //Thread's ID )4e8LO
boolean bDownOver = false; //Downing is over B6yTD7
boolean bStop = false; //Stop identical 11((b
FileAccessI fileAccessI = null; //File Access interface qN"Q3mU^h*
^7SE2Zi
T!ww3d
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException (UB?UJc
{ Ab In\,x
this.sURL = sURL; YW2h#PV6_
this.nStartPos = nStart; sW,JnR
this.nEndPos = nEnd; h.*v0cq:
nThreadID = id; dJjkH6%}
fileAccessI = new FileAccessI(sName,nStartPos);//定位 M-8`zA2
} #I"s{*
_M) G
jcbq#
public void run() F;L8FL-
{ 'N3)>!Y:8
while(nStartPos < nEndPos && !bStop) Fy$f`w_H@
{ 2oo/KndU
9Wv}g"KY0
(2ZkfN
try{ bP Q=88*
URL url = new URL(sURL); 6E#znRi6IE
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); dSI<s^n
httpConnection.setRequestProperty("User-Agent","NetFox"); +^DDWVp
String sProperty = "bytes="+nStartPos+"-"; Z0[d;m*
httpConnection.setRequestProperty("RANGE",sProperty); .>a [
Utility.log(sProperty); {SkE`u4Sz
f#kT?!sP
!<3!ORFO
InputStream input = httpConnection.getInputStream(); 0Lf4^9N
//logResponseHead(httpConnection); RKPX*(i~
U38~m}c
:Y Ki
byte[] b = new byte[1024]; +# 3e<+!F
int nRead; '.wb= C
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) q-s(2C
{ `=$p!H8
nStartPos += fileAccessI.write(b,0,nRead); i IM\_<?
//if(nThreadID == 1) I.[Lv7U-
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); }/lyrjV
} w>o/)TTJL
E)`:sSd9
}P'c8$
Utility.log("Thread " + nThreadID + " is over!"); v!W{j&N
bDownOver = true; PX*}.L *x
//nPos = fileAccessI.write (b,0,nRead); 1\a.o[g3e
} Ms#rvn!J
catch(Exception e){e.printStackTrace ();} N%F4ug@i
} suS[P?4
} @THa[|(S
PJYUD5
wF9L<<&B
//打印回应的头信息 O6ph_$nt.
public void logResponseHead(HttpURLConnection con) [MuZ^'dR
{ ?t5<S]'r$
for(int i=1;;i++) UqD ]@s`
{ /i~x.i3
String header=con.getHeaderFieldKey(i); zI0d
if(header!=null) S Rk%BJ? ~
//responseHeaders.put(header,httpConnection.getHeaderField(header)); Ci4;e
Utility.log(header+" : "+con.getHeaderField(header)); H:)_;k
else @^Rl{p
break; UM/!dt}DnF
} y 2)W"PuG
} 6e8 gFQ"w2
.DI?-=p|_#
osl\j]U8
public void splitterStop() &1Cs'
{ ,+5:}hR+
bStop = true; d'"|Qg_'
} F{4v[WP)
$A`m8?bY
dVUe!S`
} B Dp")[l
-p?&vQDo`
CBv0fQtL
/* 9Z21|5
**FileAccess.java JA*+F1s
*//文件访问(定位，写) 0'HQ=pP
package NetFox; ah%Ws#&
import java.io.*; <DP8a<{{
$ x:N/mMu`
d@p#{ -
public class FileAccessI implements Serializable{ =P%&]5ts
Q6RTH
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 ;NH^+h
RandomAccessFile oSavedFile; $H)QUFyC
long nPos; t.dr<
|dz"uIrT
X5\xq+Ih
public FileAccessI() throws IOException e=l:!E10
{ /z_]7]
this("",0); h5rR44
} BN `2UVH
m8;w7S7,j~
|Iwglb!k
public FileAccessI(String sName,long nPos) throws IOException |lcp (u*u
{ ="5D}%
oSavedFile = new RandomAccessFile(sName,"rw"); c6lCF &
this.nPos = nPos; [_nOo`
oSavedFile.seek(nPos); 7nPcm;Er
} FZ?:BX^
:EAh%q
4y#XX[2Wj
public synchronized int write(byte[] b,int nStart,int nLen) -pIz-*
{ yQ$]`hr;
int n = -1; uorX;yekC
try{ %S"85#R5E
oSavedFile.write(b,nStart,nLen); tRpY+s~Fq
n = nLen; k qL.ZR
} 4g"%?xN
catch(IOException e) h=0a9vIXF
{ P%)r4+at
e.printStackTrace (); 6Iqy"MQuq
} pr,,E[
)AxD|A
I/XSW#
return n; p20JUzy
} Scx!h.\5
i6KB\W2
Q3(ulgl]
} @,n)1*{P
ol*,&C:{
D;NL*4zt
/* F3EAjO)ch
**SiteInfoBean.java Uns%6o
*/ :09NZ !!
package NetFox; Ku%tM7ad
Ny^f'tsA
}%8ZN :
public class SiteInfoBean { 0cE9O9kE
0U@#&pUc
}L)[>
private String sSiteURL; //Site's URL IJ&Lk=2E]
private String sFilePath; //Saved File's Path W-l+%T!
private String sFileName; //Saved File's Name xa@$cxt
private int nSplitter; //Count of Splited Downloading File @<{%r
B=r DU$z
^hiY6N &
public SiteInfoBean() K<wFr-z
{//nSplitter的缺省值为5 |~e"i<G#
//default value of nSplitter is 5 4hy-M>!D|
this("","","",5); >]pZ;e$
} |67Jw2
mLqqo2u
zQ|2D*W
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) [9${4=Kq
{ J?w_DQa
sSiteURL= sURL; YD'gyP4
sFilePath = sPath; XQ]vJQYIR
sFileName = sName; Q $}#&
this.nSplitter = nSpiltter; 9gcW;
XZb=;tYo
o6px1C:
} 6qHD&bv\%C
y\Aa;pL)RQ
Tc/^h4xH
public String getSSiteURL() u"=]cBRWL6
{ oj - `G
return sSiteURL; [j-?)
} n2bhCd]j<b
iRnjN
\ saV8U7B
public void setSSiteURL(String value) pOXI*0_g.
{ TvDSs])
sSiteURL = value; x[)-h/&Fh
} RJ'[m~yl5X
nsRCDUCi
xqzeBLU
public String getSFilePath() .DhI3'Jrl
{ @01.Pd
return sFilePath; iHGVR
} A.vAk''(}+
|${4sUR
7.hBc;%2u
public void setSFilePath(String value) bE/|&8
{ ; R}>SS'
sFilePath = value; J:N(U0U
} iz#R)EB/g
o>r P\
~i"=:D
public String getSFileName() F<,pAxl~@
{ *~)6 sm
return sFileName; T;92M}\
} ?Fl}@EA#M
BA c+T
KMj\A d
public void setSFileName(String value) }#FV{C]
{ wuH*a3(
sFileName = value; x vs=T
} .jCGtR )%
X[o+Y@bc
!0,q[|m
public int getNSplitter() Wlhh0uy
{ >K9Ia4I,
return nSplitter; fEZuv?@
} <?KPyg2
=7<JD}G
lV$JCNe
public void setNSplitter(int nCount) LS[o7!T(
{ \#HW.5
nSplitter = nCount; JD$g%hcVZa
} YGo?%.X
} 4u:SE
}gkLO TJ/,
uvbVb"\"Yk
/* P\j\p =
**Utility.java =y][j+WH
*/ }=/zG!+
package NetFox; @:}c(j
zWEPwOlI1P
O`@Nl
public class Utility { Fa%1]R
lnyb4d/
eM<N?9s
public Utility() *6/IO&y1a
{ B>fZH\Y
y0d=
efXnF*Z
} j;3I`:
N(7XILC
//线程睡眠 Z\nDR|3
public static void sleep(int nSecond) A9.TRKb=8
{ ^O_Z5NbC3
try{ spV7\Gs.@
Thread.sleep(nSecond); ]I\GnDJ^
} =P(*j7=
catch(Exception e) f!x9%
{ 7l53&,s
e.printStackTrace (); L!cOg8Z
} +Uq|Yh'Q
} JY"jj}H]|
,.<mj !YE
//日志 [./FzlAs
public static void log(String sMsg) ?@ oF@AEx=
{ KW .4 9
System.err.println(sMsg); cqG6di7#
} pp@ Owpb
V'i-pn2gyu
'#+&?6p
public static void log(int sMsg) 0vv~G\yM
{ 0nb%+],pX
System.err.println(sMsg); Ek L2nI
} u_k[<&$
} iJzBd7
WWunS|B!
`dZ|Ko%k
/* [J,.?'V
**TestMethod.java no*)M7
*/ ~&<#H+O
package NetFox; 4CM'I~
RCWmdR#}V
h!w::cV
public class TestMethod { 8}0wSVsxV$
<O1R*CaP
sy"}25s
public TestMethod() 3k1e
{ ///xx/weblogic60b2_win.exe MKBDWLCB
try{ c2P}P* _
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); JXc.?{LL
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); f!'i5I]
SiteFileFetch fileFetch = new SiteFileFetch(bean); fp [gKRSF
fileFetch.start(); D>7a0p784
} "/'3I/}
catch(Exception e){e.printStackTrace ();} (7R?T}
y#GHmHeh
Cy;UyZ
} q}LDFsU
1wR[nBg*|
oXm !
public static void main(String[] args) IXy6Yn9l
{ WE) *~5
new TestMethod(); *~^63Nx!
} 0>{ ]*
} ?h}NL5a
点击下载更多相关资料