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)); M\{n+r-m
} MtkU]XKGT
for(int i=0;i<nEndPos.length-1;i++) &nIu^,.
{ F85_Lz4
nEndPos = nStartPos[i+1]; '=0}2sF>
} ;<Q%d~$xy}
nEndPos[nEndPos.length-1] = nFileLength; 4&W?:=H2
} mB-,\{)
} 'xH^ksb"
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T-N>w;P
//启动子线程 JP8}+
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; Et3I(X3
for(int i=0;i<nStartPos.length;i++) d?7?tL2
{ `XxnQng
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), &_L%wV|[
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), l~E~!MR
nStartPos,nEndPos,i); Ef]Hpjvp
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 3en9TB
fileSplitterFetch.start(); mG S4W;
} :|;@FkQ
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), ^}+\52w
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); >._d2.Q'
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", Uxjc&o
nEndPos = " + nFileLength); -leX|U}k
// fileSplitterFetch[nPos.length-1].start(); Q]9$dr=Kk0
r *K
!JA;0[;l=
//等待子线程结束 Cu7{>"
//int count = 0; 529b. |
//是否结束while循环 =Pv_,%
boolean breakWhile = false; ~ *&\5rPb
y?OP- 27y
\:;MFG'
while(!bStop) irQ'Rm[
{ L('1NN2
write_nPos(); $e+sqgU
Utility.sleep(500); AERJ]$\
breakWhile = true; -+"#G?g
B[Lm}B[
]LB_ @#
for(int i=0;i<nStartPos.length;i++) c9+G Qp
{ G[KjK$.Ts?
if(!fileSplitterFetch.bDownOver) [1rQ'FBB^1
{ =muQ7l:(
breakWhile = false; {JfQQP&FV
break; |<Ls;:5.
} IHTimT?
} p{Q6g>?[
if(breakWhile) vX:}tir[
break; 9[qOfIny
d<-f:}^k0
$!O@Z8B
//count++; ?I?G+(bq
//if(count>4) |2do8z
// siteStop(); tz):$1X_
} ZeV@ X
S"!6]!~^
ZN8j})lE
System.err.println("文件下载结束！"); YNBM\Q
} =2&\<Q_Fi
catch(Exception e){e.printStackTrace ();} XO]^+'U}p
} AQZ<,TE0,
bqbG+g
5Od%Jhtt
//获得文件长度 PIH\*2\/
public long getFileSize() 7.29'
{ 7wj2-BWa
int nFileLength = -1; ]ogifnwv
try{ $5pCfW8>
URL url = new URL(siteInfoBean.getSSiteURL()); ZO/e!yju
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); ebze_:
httpConnection.setRequestProperty("User-Agent","NetFox"); +iC:/CJL
(1z"=NCp
]({-vG\m
int responseCode=httpConnection.getResponseCode(); 5qrD~D'
if(responseCode>=400) |:S6Gp[\O
{ 2}&ERW
processErrorCode(responseCode); IRbyW?/Xv
return -2; //-2 represent access is error GDLi?3q
} ^(JrOh'
=n,;S W
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String sHeader; U =J5lo
{L;sF=d
;VLDXvGd
for(int i=1;;i++) v\@qMaPY
{ 5[;[Te9=S
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); fAJyD`]Z
//Utility.log(in.readLine()); Rs=Fcvl
sHeader=httpConnection.getHeaderFieldKey(i); g!^N#o
if(sHeader!=null) ~IZ-:?+S^
{ +,spC`M6h
if(sHeader.equals("Content-Length")) N1'"7eg/
{ ^ =C>
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); O::FB.k
break; J#`7!
} 6SCjlaGW5
} |*?N#0s5h
else W5u5!L/
break; Fu.aV876\f
} &6\&McmkX
} yu6~:$%H
catch(IOException e){e.printStackTrace ();} 9(]_so24,
catch(Exception e){e.printStackTrace ();} THwM',6
CzV;{[?~;
z#+WK|a
Utility.log(nFileLength); \hX,z =
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{v*4mT
return nFileLength; |V5BL<4
} !EIH"`>!
P"NI> HM
o'lG9ePM|
//保存下载信息（文件指针位置） `p\%ha!,w
private void write_nPos() /D"T\KNWr
{ im*sSz 0 (
try{ 7=fM}sk
output = new DataOutputStream(new FileOutputStream(tmpFile)); "\*)KH`C
output.writeInt(nStartPos.length); a>GA=r
for(int i=0;i<nStartPos.length;i++) 3.YH7rN
{ | +;ZC y
// output.writeLong(nPos); DG;u_6;JR
output.writeLong(fileSplitterFetch.nStartPos); :kHk'.V1(
output.writeLong(fileSplitterFetch.nEndPos); lH3.q4D 5
} -=lm`X<:
output.close(); /6rjGc
} .!~ysy
catch(IOException e){e.printStackTrace ();} a >fA-@
catch(Exception e){e.printStackTrace ();} cPtDIc,
} F,_cci`p
),{3LIr
2M+RA}dX
//读取保存的下载信息（文件指针位置） /eHf8l
private void read_nPos() lSR\wz*Fk
{ L~ax`i1:"
try{ XF: wsC
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); EG\L]fmD
int nCount = input.readInt(); U>t:*SNC*
nStartPos = new long[nCount]; $MasYi
nEndPos = new long[nCount]; NATi)A"TZ
for(int i=0;i<nStartPos.length;i++) :(enaHn#~
{ .U(6])%;@
nStartPos = input.readLong(); iY>xx~V
nEndPos = input.readLong(); 5V<6_o
} 9y\nO)\Tv
input.close(); w8D8\`i!"
} _LF'0s*
catch(IOException e){e.printStackTrace ();} pXNhU88
catch(Exception e){e.printStackTrace ();} `x=kb;
} DQhHU1
n^QDMyC;I
m@nGXl'!
private void processErrorCode(int nErrorCode) Rb<| <D+
{ d '2JMdbc
System.err.println("Error Code : " + nErrorCode); > X AB#
} (NUXK
f]1 $`
>kAJS??
//停止文件下载 M(8xwo-W
public void siteStop() 4`~OxL
{ ,dba:D=l
bStop = true; `*CoVx~fk
for(int i=0;i<nStartPos.length;i++) b5g^{bzwu
fileSplitterFetch.splitterStop(); \nOV2(FAT
r;f\^hVy
HV`u#hZ7C
} %/zHL?RqJ
} z*nztvY@e
//负责部分文件的抓取 rREev
**FileSplitterFetch.java yzpa\[^
*/ 3>(~5
package NetFox; WL%T nux
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y%--/;
import java.io.*; @lB1t= D
import java.net.*; Nt+UL/1]
R7Tl1!,h
XF{2'x_R
public class FileSplitterFetch extends Thread { LzXIqj'H7T
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String sURL; //File URL ,,XHw;{
long nStartPos; //File Snippet Start Position w;VUP@Wm
long nEndPos; //File Snippet End Position Y\!:/h]E&
int nThreadID; //Thread's ID "~C\Z} ;
boolean bDownOver = false; //Downing is over |RpZr!3V
boolean bStop = false; //Stop identical qyyLU@hd
FileAccessI fileAccessI = null; //File Access interface i_6wD
8Pom^QopK
(`n*d3
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException tSDp>0yZ3
{ E3Z>R=s
this.sURL = sURL; "6$+B/5
this.nStartPos = nStart; g'L$m|
this.nEndPos = nEnd; ^(xVjsHp#
nThreadID = id; 7.5\LTM>9e
fileAccessI = new FileAccessI(sName,nStartPos);//定位 17Q* <iCs
} W6B o\UK
!/&~Feb
tORDtMM9+
public void run() GmGq69]J*
{ n;b9f|&z
while(nStartPos < nEndPos && !bStop) fZd~},X
{ :+DAzjwO<
:?%_JM5U
>fR#U"KPAB
try{ 9DXu*}
URL url = new URL(sURL); ]:^kw$
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); d@|j>Z
httpConnection.setRequestProperty("User-Agent","NetFox"); '9wD+'c=A
String sProperty = "bytes="+nStartPos+"-"; s|!b: Ms`
httpConnection.setRequestProperty("RANGE",sProperty); D/{Spw@
Utility.log(sProperty); _ )^n[_E
Qzk/oHs
A[d'*n[
InputStream input = httpConnection.getInputStream(); ] )x z
//logResponseHead(httpConnection); Iq": U
9aqFdlbY
A%M&{S'+|X
byte[] b = new byte[1024]; QQjMC'
int nRead; }\ui}\
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) 5Q72.4HH
{ =TI|uD6T
nStartPos += fileAccessI.write(b,0,nRead); eWx6$_|
//if(nThreadID == 1) d>4e9M"
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); B<'V7#L_
} H+2J.&Ch
PZA;10z
$j}sxxTT
Utility.log("Thread " + nThreadID + " is over!"); e$(i!G)
bDownOver = true; *DoEDw
//nPos = fileAccessI.write (b,0,nRead); ~h[lu^ZSi
} {_MU0=7c\
catch(Exception e){e.printStackTrace ();} '*p-`
} cfe[6N
} =Jl1D*B*
Pq7tNM E
+XRv iHA`
//打印回应的头信息 zsRN\U
public void logResponseHead(HttpURLConnection con) R}+/jh2O|
{ zZh`go02E
for(int i=1;;i++) M!6bf
{ TbU9 <mY
String header=con.getHeaderFieldKey(i); Ez1*}
if(header!=null) *&2#;mf3
//responseHeaders.put(header,httpConnection.getHeaderField(header)); qV$',U*+T
Utility.log(header+" : "+con.getHeaderField(header)); $X&OGTlw^
else E.% F/mM
break; %J%gXk}]
} d`nS0Tf'
} r@<;
6nSk,yE'hE
w)8@Tu:Q
public void splitterStop() +ow ^xiD
{ ~ pdf'
bStop = true; mg,f>(
} .y2<2eW
}>XSp)"{l
hJ4.:
} <,hBoHZSL
ze\~-0ks+
IKr7"`
/* !<6wrOMaO
**FileAccess.java +m7x>ie)
*//文件访问(定位，写) 6$dm-BI
package NetFox; $-AvH(@
import java.io.*; >`\*{]
OB^2NL~Q~
@Q1jH~t
public class FileAccessI implements Serializable{ ?RzT0HRd
X9gC2iSs]
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 Z "=(uwM
RandomAccessFile oSavedFile; O}D8
long nPos; CijS=-
n*6s]iG V
`U1%d7[vY
public FileAccessI() throws IOException S&uL9)Glb
{ I~qiF%?d
this("",0); 4K;j:ZJ"x
} ry]7$MQyV
v#+w<gRq
h{xERIV1u
public FileAccessI(String sName,long nPos) throws IOException ?-84_i
{ XP^6*}H.*
oSavedFile = new RandomAccessFile(sName,"rw"); 7~Ga>BK
this.nPos = nPos; rYS D-Kq
oSavedFile.seek(nPos); *f#4S_ws`
} "AK3t' jF*
jrl6):x
E\*",MGL
public synchronized int write(byte[] b,int nStart,int nLen) 9cmJD5OO
{ +?:V\niQI
int n = -1; \ +xIH
try{ 1;gSf.naG
oSavedFile.write(b,nStart,nLen); 2!otVz!Mh
n = nLen; ">QY'r
} bgK(l d`
catch(IOException e) rpT<cCem1
{ N]<gHGj}
e.printStackTrace (); C|J1x4sb@
} 85{vz|(':
~&/Gx_KU
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return n; C|zH {.H
} wf@2&vJ
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?.4l1X6Ba
} Aii[=x8
.KsvRx
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/* u"gp">
**SiteInfoBean.java `j![
*/ *a%PA(%6
package NetFox; ,s76]$%4
Q8q_w2s,
Pvw%,=41O
public class SiteInfoBean { w$ {
7dJaWD:&
B~#@fIL
private String sSiteURL; //Site's URL y)E2=JQA/
private String sFilePath; //Saved File's Path ):@%xoF5
private String sFileName; //Saved File's Name %nh'F6bNgv
private int nSplitter; //Count of Splited Downloading File R4(8]oUW
/6c10}f
lpUtNy
public SiteInfoBean() P.B'Gh#^
{//nSplitter的缺省值为5 %p60pn[(
//default value of nSplitter is 5 y21uvp'
this("","","",5); 2AW{qwk7
} q_&IZ,{Vk
*~uuCLv_
{ bn#:75r
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) !?*!"S-Sl
{ 3@?YTez#
sSiteURL= sURL; $@kw>2
sFilePath = sPath; F8Wq&X#r
sFileName = sName; 1[`<JCFClc
this.nSplitter = nSpiltter; c7IR06E
|u;PU`^-z
%Ab_PAw
} 3raA^d3!?
^b %8_?2m
J"%}t\Q
public String getSSiteURL() T_[\(K`w!
{ oLMi vy4
return sSiteURL; CWQ2iu<_0
} Z|%2495\
Y`?X Fy:
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public void setSSiteURL(String value) ]!aa#?Fc
{ QJM!Wx+
sSiteURL = value; 5qSZ>DZ
} 9nS!
%:?QE ;
xN8JrZE&
public String getSFilePath() Jk`)`94I
{ ok2~B._+;
return sFilePath; 2] G$6H
} m@u`$rOh
Wb)l8[=
;w(1Ydo
public void setSFilePath(String value) D])YP0|}
{ >?eTbtP
sFilePath = value; Pm(:M:a
} uE`|0
:$c:3~
h)^A3;2F
public String getSFileName() ca*[n~np
{ yGGB
return sFileName; p3FnYz-V
} vcO`j<`
\N , '+
8Vhck-wF
public void setSFileName(String value) X6GkJ R
{ /&as)
sFileName = value; A'QGTT
} Wx)U<:^e
fR%1FXpK&
qK vr*xlC
public int getNSplitter() hUvuq,LH_
{ 3;S`<
return nSplitter; 0(/D|
} /NX7Vev
`{lAhZ5
Guw|00w,Q$
public void setNSplitter(int nCount) ,]_(-tyN|
{ v#]v,C-*
nSplitter = nCount; EQ63VF
} xf"5<PTW</
} E+ 3yN\X(
Df:7P>
A a} o*
/* uoY`qF.`
**Utility.java i(yAmo9h
*/ FEZ"\|I|
package NetFox; +VLe'|
:@%-f:iDj
L@n6N|[_
public class Utility { @U3foL2\
k;_KKvQ
EH*ym#Y
public Utility() 27E9NO=
{ ,' rL'Ys
\y H3Y
/E{dM2
} 4[,B;7
#>m, Cm
//线程睡眠 ) Zb`~w
public static void sleep(int nSecond) f./m7TZ
{ omv6_DdZ
try{ hQ}7Z&O
Thread.sleep(nSecond); c\)&yGE
} cP@F #!2
catch(Exception e) ]8m_*I!
{ YP#AB]2\}
e.printStackTrace (); O(D5A?tv!
} mk%"G=w
} S`@6c$y k
^/C$L8#
//日志 1 73<x){
public static void log(String sMsg) ,d>X/kd|o
{ ?7kV+{.
System.err.println(sMsg); @9uYmkcV
} g7 Md
-<51CDw,
UhSh(E8p>
public static void log(int sMsg) 71l"m^Z3zy
{ MzR1<W{ O
System.err.println(sMsg); ewAH'H]o
} ~S^X"8(U
} `o_fUOe8a
c/=y*2,zo
r!.+XrYg
/* i,'Ka[6
**TestMethod.java O| 1f^_S/
*/ xdL/0 N3
package NetFox; 50`iCD
EO].qN-8
lbB.*oQ
public class TestMethod { Rct"\{V')n
T1(j l)
&8]#RQy{f
public TestMethod() UEEBWzH
{ ///xx/weblogic60b2_win.exe 7bonOt Y
try{ V/3 {^Fcr
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); ~[zFQ)([
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); 'n^2|"$sH
SiteFileFetch fileFetch = new SiteFileFetch(bean); ;v,9v;T
fileFetch.start(); Jm %ynW
} i!Dh&XT
catch(Exception e){e.printStackTrace ();} 3'[Rvy{
vQKn=
*U;4t/(
} X`fhln9N
,G[r+4|h
}{&ln
public static void main(String[] args) Bn~\HW\Lh
{ 's>#8;X
new TestMethod(); ,C{^`Bk-W
} 6wb^*dD92
} b8N[."~:
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