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)); !YHu
} ZW%`G@d"H-
for(int i=0;i<nEndPos.length-1;i++) 1X.1t^HH:
{ J)NpG9iN
nEndPos = nStartPos[i+1]; e[!>ezaIY
} eO G%6C%a
nEndPos[nEndPos.length-1] = nFileLength; )>p6h]]a
} o#6}?g.
} 6P|neb}
oFp&j@`k8j
sAlgp2-
//启动子线程 lsi8?91
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; &0`7_g7G
for(int i=0;i<nStartPos.length;i++) &r%3)Z8Et
{ UC@"<$'C
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), pC8i&_A
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), [NcOk,
nStartPos,nEndPos,i); Pme?`YO$x
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 9Z 4R!Q
fileSplitterFetch.start(); :g";p.~=
} XU7bWafy
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), >m!.l{*j>N
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); -2_$zk*n
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", zPYa@0I
nEndPos = " + nFileLength); ?2;G_P+
// fileSplitterFetch[nPos.length-1].start(); )I4tl/
rkl7p?
L+L9)8FJ
//等待子线程结束 06$9Uz9
//int count = 0; P0=F9`3wb
//是否结束while循环 h@d m:=ul
boolean breakWhile = false; C-Z,L#
}1dh/Cc`
Tp13V.|
while(!bStop) LAeXe!y
{ _T$\$v$ {
write_nPos(); T-TH. R
Utility.sleep(500); -C+vmY*@
breakWhile = true; JhcS
GZo4uwG@a
<~OyV5:6
for(int i=0;i<nStartPos.length;i++) ND>}t#^$
{ _#:1Axx1
if(!fileSplitterFetch.bDownOver) }d(6N&;"zN
{ u@B"*V~K
breakWhile = false; n21J7;\/+
break; lTXU
} #UQ[8e
} sh1()vT
if(breakWhile) U|nk86r
break; 9@06]EI_
,R+u%bmn#
($kwlj~c
//count++; JSU\Hh!
//if(count>4) Y$^\D'.k
// siteStop(); 2OTpGl
} Ipe;%as#
85mQHZ8aR
E_oe1C:
System.err.println("文件下载结束！"); U?QO'H5
} rL=$WxdPU
catch(Exception e){e.printStackTrace ();} j*{bM{~T<
} cx|j _5%i
$/H'Dt6x
d9(FwmE
//获得文件长度 zBbTj IFQ
public long getFileSize() ?*4zNhL
{ "^H+A-R[
int nFileLength = -1; \<} nn?~n
try{ L;"<8\vWB
URL url = new URL(siteInfoBean.getSSiteURL()); jo^*R'}
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); sq_:U_tJ
httpConnection.setRequestProperty("User-Agent","NetFox"); pP @#|T
d\v _!7
r!S iR(
int responseCode=httpConnection.getResponseCode(); o2~x'*A0I
if(responseCode>=400) Gm.hBNgp
{ mI# BQE`p6
processErrorCode(responseCode); _OY;SJ(
return -2; //-2 represent access is error 5IMH G%W7
} ZeO>Ag^
Dfea<5~^z
`4CRpz
String sHeader; <T wq{kt
/ @&Sqv4?
3jNcL{
for(int i=1;;i++) 5+UiAc$
{ dY,'6JzC
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); vl<J-+|0C
//Utility.log(in.readLine()); ?P5D!b:(
sHeader=httpConnection.getHeaderFieldKey(i); "hfwj`U
if(sHeader!=null) I9E@2[=!
{ RA6D dqT~
if(sHeader.equals("Content-Length")) C\{4<:<_&
{ !cZsIcIe
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); xn"g_2Hi
break; ^tv*I~>J!
} {x8`gP\H
} XP7A.I#q0
else 2B4c:jJ
break; ? _W*7<
} z+b~#f3
} 181P;R=}<
catch(IOException e){e.printStackTrace ();} t`AD9 H"\!
catch(Exception e){e.printStackTrace ();} N]duv~JS
1jL?z6S
1pV"<,t
Utility.log(nFileLength); R/#*~tPi8
MWl@smRh
`&_qK~&/X
return nFileLength; 073(xAkL{
} x\jHk}Buj
[V2l&ZUni
H)S3/%.|
//保存下载信息（文件指针位置） gDsZbmR
private void write_nPos() ^Z*_@A_v
{ rnr7t \a~]
try{ c|7Pnx%gT
output = new DataOutputStream(new FileOutputStream(tmpFile)); R8 m/Nt2
output.writeInt(nStartPos.length); 7-5q\[ZK
for(int i=0;i<nStartPos.length;i++) qb_V ,b9
{ d>%_<pw
// output.writeLong(nPos); vl#/8]0!
output.writeLong(fileSplitterFetch.nStartPos); )L{\k$r!EM
output.writeLong(fileSplitterFetch.nEndPos); C?O{l%0
} E8xXr>j>#
output.close(); U0rz 4fxc
} &^<94l
catch(IOException e){e.printStackTrace ();} I$Z"o9"
catch(Exception e){e.printStackTrace ();} C>+UZ
} iJYr?3nw;
F JzjS;
-l\@50,D
//读取保存的下载信息（文件指针位置） zme:U![
private void read_nPos() 0h7\zoZ5
{ 1)r1/0
try{ IQM!dC
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); Cxh9rUe.
int nCount = input.readInt(); V><P`
nStartPos = new long[nCount]; y?rsfIth`
nEndPos = new long[nCount]; s#Le`pGoW
for(int i=0;i<nStartPos.length;i++) 6?_Uow}
{ 0`x<sjG\q
nStartPos = input.readLong(); ecHy. 7H
nEndPos = input.readLong(); ?eu=0|d
} 3]!(^N>V
input.close(); r[gV`khka
} +q4T];<
catch(IOException e){e.printStackTrace ();} '.iUv#j4Sh
catch(Exception e){e.printStackTrace ();} rdK.*oT
} PQfx0n,
v uJ~Lg{
}$7Hf+G
private void processErrorCode(int nErrorCode) {*|yU"
{ mz#(\p=T
System.err.println("Error Code : " + nErrorCode); hE=cgO`QU
} %pMW5]H
+?c&Gazi
zYep V
//停止文件下载 TqlUe@E
public void siteStop() +@!9&5SA
{ / g&mDYV|
bStop = true; I@hC$o
for(int i=0;i<nStartPos.length;i++) :g,rl\S7
fileSplitterFetch.splitterStop(); aA:Ky&5e
lyib+Sa ?`
=Xp3UNXg
} #[A/zH|xvV
} 7.5G4
//负责部分文件的抓取 TWn7&,N
**FileSplitterFetch.java aqMZ%~7
*/ $)'{+1
package NetFox; 7mu%|!
GxvVh71zP
9oaq%Sf
import java.io.*; BFMM6-Ve
import java.net.*; W6a2I
5Zq- |"|
jReI+ pS
public class FileSplitterFetch extends Thread { I($u L@$
7Fq|Zc`P
*kDXx&7B$
String sURL; //File URL @50Js3R1q
long nStartPos; //File Snippet Start Position v.\&gn(
long nEndPos; //File Snippet End Position ]$z~;\T
int nThreadID; //Thread's ID o&>0 pc
boolean bDownOver = false; //Downing is over KR{kn[2|Q
boolean bStop = false; //Stop identical ] $%{nj<
FileAccessI fileAccessI = null; //File Access interface ?56Zw"89
\O^= Z{3y
bT8BJY%+
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException o77HRX
{ '- Z4GcL
this.sURL = sURL; 9J>DLvl;
this.nStartPos = nStart; +oyc9PoXF
this.nEndPos = nEnd; &AoWT:Ea
nThreadID = id; >8RIMW2
fileAccessI = new FileAccessI(sName,nStartPos);//定位 x.d9mjLN8m
} tmm\V7sJ
p1 o?^A&
>CYg\vas!
public void run() i4->XvC
{ h<6r+*T' p
while(nStartPos < nEndPos && !bStop) E[$['0
{ @ #V31im"N
T*$uc,
%D&FnTa
try{ /]YK:7*98
URL url = new URL(sURL); oVLz7Y[JE
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); jSddjs
httpConnection.setRequestProperty("User-Agent","NetFox"); oXGf#>keg
String sProperty = "bytes="+nStartPos+"-"; p*>[6{$3)O
httpConnection.setRequestProperty("RANGE",sProperty); 0|HhA,u
Utility.log(sProperty); D]4?UL
9gWQGkql
a5&wS@) ;
InputStream input = httpConnection.getInputStream(); {B[i|(xQx
//logResponseHead(httpConnection); b?r0n]
%';n9M
/a]+xL
byte[] b = new byte[1024]; 3 \kT#nr
int nRead; I{M2nQi
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) {8t;nsdm!
{ Ue8_Q8q5
nStartPos += fileAccessI.write(b,0,nRead); ; I=z
//if(nThreadID == 1) E fqa*,k
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); >(\[$
} ZkqC1u3
!FO92 P16
0wOgQ n
Utility.log("Thread " + nThreadID + " is over!"); hzPpw.
bDownOver = true; hR. EZ|.
//nPos = fileAccessI.write (b,0,nRead); PUa~Apj'
} |=7%Edkd
catch(Exception e){e.printStackTrace ();} "+|>nA=7
} 4h(aTbHaQ
} >q]r)~8F^
NMOTWA}2
xNjA>S\]W5
//打印回应的头信息 ;7qk9rz4
public void logResponseHead(HttpURLConnection con) k5<lkC2z
{ {VI%]n{M
for(int i=1;;i++) 5Lue.U%a
{ y_J{+
String header=con.getHeaderFieldKey(i); TN l$P~X>
if(header!=null) GifD>c |z
//responseHeaders.put(header,httpConnection.getHeaderField(header)); ]bRu8kn
Utility.log(header+" : "+con.getHeaderField(header)); LxMOs Nv
else gs9f2t
break; GF k?Qf{u
} !vG._7lPp
} >.B+xn=
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0{Tf;a<
public void splitterStop() |rNm_L2
{ o2%"Luf<
bStop = true; W}(dhgf
} dedi6Brl
O" T1=4
:Z&ipd!yY
} }De)_E\~
x%$Z/
+K+ == mO&
/* B{zIW'Ld
**FileAccess.java G-rN?R.
*//文件访问(定位，写) )m6=_q5@o
package NetFox; GZO,]%z
import java.io.*; f0:)
ZtIK"o-|!
dU+1@_
public class FileAccessI implements Serializable{ ,(lD5iN
Q}I.UG_
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 6W3}6p
RandomAccessFile oSavedFile; .%D] z{''
long nPos; FSH6C2
!M}&dW2
_Hkc<j/e~
public FileAccessI() throws IOException =#1/<q)L
{ KX*e2 /0
this("",0); LZ^sc
} zu*h9}
d'DS7F(c{
UY>{e>/H9
public FileAccessI(String sName,long nPos) throws IOException Ph-3,cC
{ r}XD{F}"
oSavedFile = new RandomAccessFile(sName,"rw"); E4 JS
this.nPos = nPos; f *)t<1f
oSavedFile.seek(nPos); Ndx='j0
} t-/%|@?D
RCoz;|c`P
h~<#1'/<
public synchronized int write(byte[] b,int nStart,int nLen) .llAiv
{ [D/q%
int n = -1; 3`-[95w
try{ t$s)S>
oSavedFile.write(b,nStart,nLen); Rk`c'WP0*
n = nLen; tXfB.[U
} {K:/(\
catch(IOException e) |"l g4S%
{ 3):7mE(
e.printStackTrace (); I8?egDkk
} 6:QJ@j\
GY0<\-
0z\=uQ0
return n; 23+>K
} )v'3pTs2
DfqXw^BKD
m@"!=CTKd
} 1eKJ46W
\QYs(nm?k
yKq;EcVx
/* $^`hu%s,~
**SiteInfoBean.java $YL}rM
*/ Jb_/c``
package NetFox; !07$aQYcd
e3',? 5j
<:/V`b3a
public class SiteInfoBean { >>&~;PG[
[<OMv9(l'o
}8 ,b;Q
private String sSiteURL; //Site's URL !'n+0
private String sFilePath; //Saved File's Path |RHX2sso
private String sFileName; //Saved File's Name cj5pI?@e)
private int nSplitter; //Count of Splited Downloading File :qw:)i
\b~zyt6-
vE{QN<6T
public SiteInfoBean() %lEPFp
{//nSplitter的缺省值为5 YIjBKh
//default value of nSplitter is 5 c9DX
this("","","",5); |1rBK.8
} 'gQm%:qU3r
LP.-
uy7)9w
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) V@T G"YF
{ sE]eIN
sSiteURL= sURL; :Im_=S[0
sFilePath = sPath; c1b@3
sFileName = sName; qCIZW
this.nSplitter = nSpiltter; awMm&8cIM
LvE|K&R|
)]rGGNF*
} KvC:(Vqj
]ujH7T
4AUY8Pxp
public String getSSiteURL() H| IsjCc
{ rt t?4
return sSiteURL; 3Qn! `
} babDLaC@
?T?%x(]I
+)Z,%\)Z
public void setSSiteURL(String value) vPpbm
{ IRXpk6|
sSiteURL = value; (z+[4l7
} oM QH-\(}
:9]23'Md
NIQa{R/H
public String getSFilePath() H=7dp%b"
{ Mm|HA@W^
return sFilePath; rcNM,!dZ
} ^!E;+o' t
dzggl(
+qjW;]yxP
public void setSFilePath(String value) gXs@FhR0
{ ]TqcV8Q~
sFilePath = value; vg *+>lbA
} et/mfzV
CSwNsFDR%
Hm%[d;Z7
public String getSFileName() V<nh+Q3<d
{ Zna }h{
return sFileName; TkmN.@w_C
} Za4 YD
C n4|qX"&t
K\=bpc"Fy
public void setSFileName(String value) bbS'ZkB\
{ eBtkTWx5[/
sFileName = value; "fS9Nx3
} _U/etlDTO
2-UZ|y
X[grVe
public int getNSplitter() T\. 8og
{ E=HS'XKu[K
return nSplitter; }MuXN<DDb
} v#=WdaNz
tE<L4;t
R# mZYg
public void setNSplitter(int nCount) 0Rrz
{ z[] AH#h
nSplitter = nCount; es&+5
} oa1&9
} l&U3jeW-o
eHd{'J<
[uZU p*.V
/* />.&
**Utility.java 7u o4F=%
*/ mpK|I|-
package NetFox; t[)z/[m
x8tRa0-q
)<IbQH|_
public class Utility { =:o)+NE
uh`~K6&*\w
TJLz^%t
public Utility() ]-L/Of6F)|
{ B~yD4^
Qh?q0VKU^
s13Iu#
} $?ke "
6L'cD1pu
//线程睡眠 :8yrtbf$
public static void sleep(int nSecond) D;d'ss;
{ f5mk\^
try{ gd#
Thread.sleep(nSecond); %Xkynso~
} |'Ve75 W6u
catch(Exception e) FSc730rM
{ P^VV8Z>\&
e.printStackTrace (); HgduH::\#
} "c1vW<;
} %D e<H*
\'BKI;
//日志 qd!$nr
public static void log(String sMsg) .E[k}{k,
{ ;2#HM^Mu
System.err.println(sMsg); ax'Dp{Q
} LTBqXh
3_vggK%
:,]%W $f=
public static void log(int sMsg) nb(#;3DQ
{ jk) V[7P
System.err.println(sMsg); 9FH=Jp
} 93[`1_q7\
} LOR$d^l
^Q2K0'm5
?HZ+fS,-
/* :%!=Ej.J
**TestMethod.java )k0bP1oGS
*/ 4'G<qJoc
package NetFox; }[D[ZLv
|Z#)1K
3U1xKF
public class TestMethod { ^9qncvV
|F9/7 z\5+
B@.U\.
public TestMethod() [rE,fR
{ ///xx/weblogic60b2_win.exe TX*s T
try{ z}u
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); EC?!%iO`
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); sL+/Eeb` c
SiteFileFetch fileFetch = new SiteFileFetch(bean); /!jn$4fd:
fileFetch.start(); nVs0$?}
} evu@uq
catch(Exception e){e.printStackTrace ();} c|96;=z~
v<3i~a
&[23DrI8
} lq1pgM?Kf
=Lp0i9c
^J@Y?CQl\
public static void main(String[] args) [8O`VSV3
{ vTP'\^;
new TestMethod(); /$+ifiFT
} :+!hR4Z~\;
} CO5?UgA
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