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)); H8^(GUhyp
} eRstD>r
for(int i=0;i<nEndPos.length-1;i++) uk]$#TV*q>
{ uaGk6S
nEndPos = nStartPos[i+1]; +I:Unp
} };bEU wGWf
nEndPos[nEndPos.length-1] = nFileLength; nQtWvT
} uR4z&y
} PbgP\JeX
"f2$w
}J`w4P
//启动子线程 Nk 8B_{
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; O67W&nz
for(int i=0;i<nStartPos.length;i++) mPK:R^RjG&
{ o>i4CCU+
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), B6As,)RjD:
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), 4*#18<u5
nStartPos,nEndPos,i); qI9z;_,gNz
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); K5VWt)Z#
fileSplitterFetch.start(); m6K}|j
} 6NuD4Ga
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), S_4?K)n #
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); ,~$p,ALwN7
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", ~'H]jN
nEndPos = " + nFileLength); n;C :0
// fileSplitterFetch[nPos.length-1].start(); _|\~q[ep
GPv1fearl
82qoGSD.
//等待子线程结束 EHIF>@TZ
//int count = 0; wn, KY$/
//是否结束while循环 qzLPw*;
boolean breakWhile = false; ~i{(<.he
f4b/NG|
)Y0!~# `
while(!bStop) .x.]`b(
{ ")5":V~fN
write_nPos(); syj0.JD
Utility.sleep(500); l -mfFN
breakWhile = true; {n.PF8A5X
El".I?E*
7\[@m3s
for(int i=0;i<nStartPos.length;i++) M}-Rzc
{ |?xN\O^#}
if(!fileSplitterFetch.bDownOver) aQcleTb
{ $am$EU?s
breakWhile = false; Xp% v.M
break; wqs?828x
} Hqx-~hQO
} mzKiO_g}
if(breakWhile) hJ? O],4J
break; 9(7-{,c
_p/UsJ
aEWWP]
//count++; ^j7Vt2-
//if(count>4) t+G#{n
// siteStop(); A#<?4&
} V>LwqS~`
.},'~NM]
yNo0ubY
System.err.println("文件下载结束！"); *W1dG#Np}
} ~?Pw& K2
catch(Exception e){e.printStackTrace ();} 2tEkj=fA-
} [Ek7b*
M `M5'f
ZzpUUH/r
//获得文件长度 LEf^cM=>
public long getFileSize() vF+7V*<
{ n\D&!y[]F
int nFileLength = -1; vX"*4m>b?+
try{ ~<5!?6Yt
URL url = new URL(siteInfoBean.getSSiteURL()); "| g>'wM*
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); @%uUiP0
httpConnection.setRequestProperty("User-Agent","NetFox"); @ioJ]$o7
E_wCN&`[
[ /b2=>
int responseCode=httpConnection.getResponseCode(); j0aXyLNX
if(responseCode>=400) y9GoPC`z
{ ]^7@}Ce_
processErrorCode(responseCode); ^|(LAjet
return -2; //-2 represent access is error 5d^sA;c
} 5m 4P\y^a
=R|HV;9 h
]|ag
String sHeader; A,<E\
>Q;l(fdj
[yQt^!;
for(int i=1;;i++) _8J.fT$${
{ p38-l'{#
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); JR21>;l#2
//Utility.log(in.readLine()); HM1Fz\Sf
sHeader=httpConnection.getHeaderFieldKey(i); p%Vt#?q
if(sHeader!=null) &`r-.&Y
{ -3*]G^y2
if(sHeader.equals("Content-Length")) 0i>5<ej,f
{ k%#EEMh
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); "Gzz4D
break; lgy<?LI\
} @Uvz8*b6
} tSUEZ62EY
else 5Ln,{vsv
break; G~[x 3L'
} 1n8/r}q'H
} &wawr2)}
catch(IOException e){e.printStackTrace ();} Q"d^_z]K
catch(Exception e){e.printStackTrace ();} &PHTpkaam
Bm<`n;m
ltSU fI
Utility.log(nFileLength); ,w4(kcg%iQ
: *#-%0
o5PO=AN
return nFileLength; rXP,\ ]r+
} AV]2euyn
my1@41 H
JyK3{wYS
//保存下载信息（文件指针位置） 3;9^
private void write_nPos() WE#^a6
{ V2EUW!gn 2
try{ f'RX6$}\1X
output = new DataOutputStream(new FileOutputStream(tmpFile)); R) h#Vc(
output.writeInt(nStartPos.length); %aCqi(.7
for(int i=0;i<nStartPos.length;i++) Ic<2QknmP
{ Wvh#:Z
// output.writeLong(nPos); ebhXak[w
output.writeLong(fileSplitterFetch.nStartPos); u&vf+6=9Dd
output.writeLong(fileSplitterFetch.nEndPos); khxnlry
} +\]\[6
output.close(); jB2[(
} v{4$D~I
catch(IOException e){e.printStackTrace ();} K5h
catch(Exception e){e.printStackTrace ();} t=iIY`Md%
} <xm7qmqI
%wy.TN
>]TWXmx/w
//读取保存的下载信息（文件指针位置） 9.-S(ZO
private void read_nPos() C{rcs'
{ ~ .g@hS8>
try{ M7~2iU<#
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); 6d}lw6L
int nCount = input.readInt(); (ZZ8L-s
nStartPos = new long[nCount]; ]_gU#,8
nEndPos = new long[nCount]; q3!bky\
for(int i=0;i<nStartPos.length;i++) lUZ+YD4
{ .`eN8Dl1
nStartPos = input.readLong(); h[Y1?ln&h
nEndPos = input.readLong(); K\r8g=U
} + &Eqk
input.close(); YD6'#(
} (w3YvG.
catch(IOException e){e.printStackTrace ();} _V6ukd"B~
catch(Exception e){e.printStackTrace ();} ouQ T
} M%m4i9~!?
d7upz]K9g
[z{1*Xc
private void processErrorCode(int nErrorCode) g!|kp?
{ =dKtV.L
System.err.println("Error Code : " + nErrorCode); _B<X`L =
} rb.N~
$UWZDD
6bC3O4Rw
//停止文件下载 _`T_">9r
public void siteStop() ?fSG'\h>
{ S,UDezxg
bStop = true; b4kgFA
for(int i=0;i<nStartPos.length;i++) Jnov<+
fileSplitterFetch.splitterStop(); T8$y[W-c
V 5mTP'
g) jYFfGfH
} ~$^XP.a.
} )ez9"# MH'
//负责部分文件的抓取 99QU3c<.
**FileSplitterFetch.java 3=j"=-=
*/ PJH&
package NetFox; rV#ch(
/U9"wvg
:$c |
import java.io.*; ;.980+i1
import java.net.*; ;e*!S}C,
%h!B^{0
sO@Tf\d
public class FileSplitterFetch extends Thread { zrb}_
Q![@c
8d'0N
String sURL; //File URL (jE9XxQY
long nStartPos; //File Snippet Start Position 6i/(5 nQ
long nEndPos; //File Snippet End Position 26h21Z16q
int nThreadID; //Thread's ID b]KBgZ
boolean bDownOver = false; //Downing is over R\[e!g*I
boolean bStop = false; //Stop identical XSLFPTDEc
FileAccessI fileAccessI = null; //File Access interface ;i+jJ4
b>ySv
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public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException Km$\:Xo
{ _t^&Ah*
this.sURL = sURL; Dlvz)
this.nStartPos = nStart; NzvXN1_%
this.nEndPos = nEnd; k<?b(&`J
nThreadID = id; dy[X3jQB
fileAccessI = new FileAccessI(sName,nStartPos);//定位 (sZ"iGn%
} 6'f;-2
ckCE1e>s
mC#>33{
public void run() 0g8NHkM:2a
{ K-Ef%a2#`
while(nStartPos < nEndPos && !bStop) gB33?
{ ;$g?T~v7
V'gh6`v
R:qW;n%AF
try{ f!X[c?Xy"
URL url = new URL(sURL); !4+<<(B=E
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 1'Dai`
httpConnection.setRequestProperty("User-Agent","NetFox"); p!%pP}I
String sProperty = "bytes="+nStartPos+"-"; OjA,]Gv6
httpConnection.setRequestProperty("RANGE",sProperty); CqC`8fD1
Utility.log(sProperty); 9\(| D#
C3g_!dUs
VIf.q)_k
InputStream input = httpConnection.getInputStream(); ;O,jUiQ
//logResponseHead(httpConnection); qHsA1<wg
N;%6:I./
f$QNg0v
byte[] b = new byte[1024]; v3>UV8c'
int nRead; m1AJ{cs
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) om>KU$g
{ 8&dF
nStartPos += fileAccessI.write(b,0,nRead); <#4h}_xA%
//if(nThreadID == 1) HZZn'u
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); w0unS`\4
} r3?o9D>
YS_;OFsd
\i&<s;
Utility.log("Thread " + nThreadID + " is over!"); *LY8D<:zs
bDownOver = true; U6s[`H3I{
//nPos = fileAccessI.write (b,0,nRead); f|(M.U-
} `Pnoxm'
catch(Exception e){e.printStackTrace ();} ~gt@P
} dj%!I:Q>u
} W2!+z{:m
#g!.T g'
2 yz _
//打印回应的头信息 _q^E,P
public void logResponseHead(HttpURLConnection con) 5!9zI+S|=`
{ Flb&B1
for(int i=1;;i++) xgtR6E^k
{ yB6?`3A:
String header=con.getHeaderFieldKey(i); -UT}/:a
if(header!=null) HxI" 8A
//responseHeaders.put(header,httpConnection.getHeaderField(header)); c:.eGH_f
Utility.log(header+" : "+con.getHeaderField(header)); &%Tj/Qx
else ySI!d|_
break; g9F?z2^
} #`s"WnP9'!
} \l3h0R
m#p'iU*va,
N{>n$v}
public void splitterStop() > Nr#O
{ #X"@<l4F
bStop = true; kG*~|ma
} fF kj+
|wj?ed$ f
8dhUBJ0_
} FN73+-:n:j
i}?>g-(
QmIBaMI#
/* 1BEHw?dLU
**FileAccess.java U/BR*Zn]*
*//文件访问(定位，写) Tm?#M&'
package NetFox; {(}By/_
import java.io.*; Y <qm{e
9_s`{(0?
rrv%~giU
public class FileAccessI implements Serializable{ [ikOb8 G#
<of^AKbt
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 KK &?gTa
RandomAccessFile oSavedFile; {VoHh_[5%
long nPos; bN@ l?w
cN9t{.m
u<&m]]*
public FileAccessI() throws IOException H>@+om
{ t |oR7qa{w
this("",0); CJI~_3+K
} ;A!BVq
7xa>
Q NVa?'0"Y
public FileAccessI(String sName,long nPos) throws IOException 8dyg1F
{ wlmRe`R
oSavedFile = new RandomAccessFile(sName,"rw"); {]|J5Dgfe
this.nPos = nPos; 0SPk|kr
oSavedFile.seek(nPos); dcT80sOC
} */DO ex"y
{1 94!S4z
0qT%!ku&
public synchronized int write(byte[] b,int nStart,int nLen) c[Zje7 @
{ E1f\%!2l
int n = -1; 7"xd1l?zz
try{ 6S\8$
oSavedFile.write(b,nStart,nLen); {FTqu.
n = nLen; @xZR9Z8]L
} RCLeA=/N@0
catch(IOException e) 4v|W-h"K
{ u>/ TE
e.printStackTrace (); 61 ~upQaR
} g$o&Udgs
;6hOx(>`=
2)~> R
return n; 1@=po)Hnp
} '[O;zJN;
uRe'%?W
da~],MN
} tFl"n;~T
&YeA:i?
P L+sR3bR
/* 1g~R/*Jo
**SiteInfoBean.java j1HW._G
*/ /|#fejPh
package NetFox; W|(1Y D
kz7(Z'pw
Fea(zJ_
public class SiteInfoBean { /JU.?M35
]jRfH(i
?b5^
private String sSiteURL; //Site's URL !$>R j
private String sFilePath; //Saved File's Path Nl(Foya%)
private String sFileName; //Saved File's Name VOh4#%Vj
private int nSplitter; //Count of Splited Downloading File EAby?51+
F1Bq$*'N$w
y L~W.H
public SiteInfoBean() -1@<=jX3_
{//nSplitter的缺省值为5 $ o#V#
//default value of nSplitter is 5 b\+`e b8_
this("","","",5); [;sRV<
} Mh 7DV
{T~#?v(
-RK- Fu<e
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) -`TEVS?`l
{ 9k[9P;"F:
sSiteURL= sURL; XHGFf_kW_N
sFilePath = sPath; LB?u8>a' I
sFileName = sName; %GIr&V4|
this.nSplitter = nSpiltter; `x%>8/
"Os_vlapHo
xFg>SJ7]
} u,Kly<0j
S?BG_J6A7
26x[X.C:
public String getSSiteURL() 1 I",L&S1
{ Ef13Q]9|
return sSiteURL; &UlWCOo8
} CQDkFQq-dq
1hNq8*|
*bpD`s @
public void setSSiteURL(String value) @2v_pJy^
{ =rX>1
sSiteURL = value; IRqy%@)
} 9490o:s
X+]G-
3%=~)7cF
public String getSFilePath() zT?D<XW>1
{ DrK{}uM
return sFilePath; y Fq&8 x<X
} =[jXe
hqkz^!rp
URbletSBQ
public void setSFilePath(String value) ?p8_AL'RS
{ >t_6B~x9
sFilePath = value; ?=fyc1
} F`]2O:[
WQO) =n
G9<X_
public String getSFileName() /fV;^=:8c
{ q?/a~a
return sFileName; T:W4$P
} )p%E%6p
w$-6-rE]d
kX2rp?{
public void setSFileName(String value) BsYa3d=}
{ YLn?.sV{[0
sFileName = value; Z0r?|G0
} O463I.XAP
-v|qZ'
zjoq6
public int getNSplitter() e6RPIg
{ TBU&6M>{3
return nSplitter; q{;:SgZ
} Nf1-!u7
k7usMVAA
a-L;*
public void setNSplitter(int nCount) *,WU?tl&
{ fIv*T[
nSplitter = nCount; -4_$lnw$
} x5*!Wx
} (qulwOt~w
sYf~c0${
G{%LB}2
/* fNZ__gO!%
**Utility.java t |A-9^t'!
*/ (0y~%J
package NetFox; WlBc.kFck
R`^_(yn>
hSyql
public class Utility { #],&>n7'
{o`]I>gb
i5,kd~%O
public Utility() y>e.~5;
{ _[ZO p ~
< F+l
C/6V9;U
} :'*~uJrR
3y8G?LL/[7
//线程睡眠 9\JF`ff_
public static void sleep(int nSecond) r#]WI|
{ $,Yd>%Y
try{ `XEr(e9
Thread.sleep(nSecond); 6MdiY1Lr!K
} ><HE;cVg?
catch(Exception e) l}sjD[2
{ W'+:'_{j:
e.printStackTrace (); n3 r3"~i
} j Dv{/)
} G?/DrnK:
_D(rI#q
//日志 2u*KM`fa`
public static void log(String sMsg) LvUj9eVb/L
{ rFYWs6
System.err.println(sMsg); _&ks1cw
} A`o8'+`C
PGV/ h
qE3UO<FA
public static void log(int sMsg) %m$Sp47
{ ?|B&M\}g
System.err.println(sMsg); a8Nh=^Py
} mmRJ9OhS
} =k`Cr0aPF
h6`6tk
UVIKQpA]A
/* uT7B#b7
**TestMethod.java 1 \6D '/G
*/ KE3;V2Ym f
package NetFox; eHNyNVz
\%N!5>cZ{
Oh6fj}eK
public class TestMethod { !lc[
+<3XJ7D
j@uOOhy
public TestMethod() e@* EzvO
{ ///xx/weblogic60b2_win.exe ?\s+EE&-
try{ /9pwZ%:<
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); !fR3(=oN
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); dNL(G%Qj+"
SiteFileFetch fileFetch = new SiteFileFetch(bean); M>ruKHipFE
fileFetch.start(); @8rx`9
} x!58cS*
catch(Exception e){e.printStackTrace ();} Y+u_IJ
} .y 1;.
.I0qGg
} Bj-:#P@
_k~KZ;l
l &5QZI0I
public static void main(String[] args) 1--C~IjJ+
{ Ayw ;N
new TestMethod(); fbKkq.w
} KP5C}ZK+s
} ?8Z0Gqt74
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