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)); R./6Q1
} K/+C6Y?
for(int i=0;i<nEndPos.length-1;i++) 10IPq#Jj
{ [gp:nxyfQm
nEndPos = nStartPos[i+1]; Iw7r}G
} ly%B!P|
nEndPos[nEndPos.length-1] = nFileLength; i O|,,;_
} rg/vxTl
} j$oZIV7
emPm^M5/K
oz-I/g3go
//启动子线程 :=eUNH
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; ucPMT0k
for(int i=0;i<nStartPos.length;i++) &it/@8yH
{ (+ anTA=
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), l*H"]6cXRL
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), n1(X%%2
nStartPos,nEndPos,i); &)jZ|Q~
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); .{Oq)^!ot
fileSplitterFetch.start(); m9cT}x&j
} r['C.S6
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 9G/2^PI
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); DJ0T5VE W3
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", \%Q rN+WQ
nEndPos = " + nFileLength); *v/*_6f*
// fileSplitterFetch[nPos.length-1].start(); :]QxT8B
E2kRt'~N
G@!9)v]9
//等待子线程结束 hP<qKVy
//int count = 0; Q 9<_:3
//是否结束while循环 >D62l*VC)
boolean breakWhile = false; r!,V_a4n
+aqo8'a
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while(!bStop) s2=X>,kz?
{ S9oGf
write_nPos(); nW'x#0-
Utility.sleep(500); !PIdw~YC
breakWhile = true; S]/+n>
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m kf{_!TK
for(int i=0;i<nStartPos.length;i++) PzDgl6C
{ Pv.@Y30
if(!fileSplitterFetch.bDownOver) ved Qwzh
{ S6tH!Z=(g
breakWhile = false; {o%R~{6
break; .Kwl8xRg
} (C@@e'e
} 3y,?>-
if(breakWhile) 7'uc;5:
break; !I_4GE,
!#qB%E]a
uZI a-b
//count++; CHI(\DXNs
//if(count>4) ;g]+MLV9
// siteStop(); 4HE4e
} +'.Q-
!;Nh7vG
7*"LW
System.err.println("文件下载结束！"); 'Sh5W%NM
} \9QOrjiw
catch(Exception e){e.printStackTrace ();} #sZes
} oyw1N;K
&[5az/Hj*
),,vu
//获得文件长度 5-^twXC&
public long getFileSize() $8r:&Iw
{ A,qG*lv
int nFileLength = -1; +(%[fW
try{ 64fG,b
URL url = new URL(siteInfoBean.getSSiteURL()); Kjw\SQ)2~
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); ow[qpP[
httpConnection.setRequestProperty("User-Agent","NetFox"); p]4 sN
3IFU{0a`
#mYxO
int responseCode=httpConnection.getResponseCode(); =YIQ _,{u
if(responseCode>=400) HXI}f\6x
{ E:k?*l
processErrorCode(responseCode); 063;D+
return -2; //-2 represent access is error (Lnh> '2
} ] ),'=@
R0}%
sXu+F2O
String sHeader; dZmq
y>8?RX8
sN2l[Ous
for(int i=1;;i++) vE(Hy&Q&
{ +)SX
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); z, [+
//Utility.log(in.readLine()); VIzZmd
sHeader=httpConnection.getHeaderFieldKey(i); q?&&:.H"?5
if(sHeader!=null) &=bI3-
{ 2-84
if(sHeader.equals("Content-Length")) |=s3a5sl
{ KK</5Aw9p
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); MzD0F#Y
break; JB<4m4-
} Jiq[VeLe
} .~J^`/o
else ^h=kJR9
break; PAkW[;GSDh
} 7I|Mq
} +F|[9o z
catch(IOException e){e.printStackTrace ();} M.xEiHz
catch(Exception e){e.printStackTrace ();} cqudF=q
Hr$5B2'
.U_=LV]C
Utility.log(nFileLength); $hio(
mz1g8M`@[D
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return nFileLength; &bQ^J%\
} 9"S3AEI
Xl;N=fc
UB}mI0/w
//保存下载信息（文件指针位置） u:ISwAp
private void write_nPos() :%{7Q$Xv<
{ Kl?1)u3^4
try{ ikQ2x]Sp
output = new DataOutputStream(new FileOutputStream(tmpFile)); rNc>1}DDS
output.writeInt(nStartPos.length); *F0N'*
for(int i=0;i<nStartPos.length;i++) iQF93:#
{ B|v fkX2f
// output.writeLong(nPos); n:P}K?lg
output.writeLong(fileSplitterFetch.nStartPos); ?3#X5WT
output.writeLong(fileSplitterFetch.nEndPos); f$|v
} xh0!H| R
output.close(); uypD`%pC
} AI2CfH#:C
catch(IOException e){e.printStackTrace ();} V 6F,X`7
catch(Exception e){e.printStackTrace ();} TL>e[PBO
} _qV_(TpS+
X}$S|1CjO
Dg`W{oj
//读取保存的下载信息（文件指针位置） [z\*Zg
private void read_nPos() :[doYizk:
{ lV8Mr6m
try{ N5^:2ag
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); +Q.[W`goV
int nCount = input.readInt(); M:x(_Lu
nStartPos = new long[nCount]; v;SJgZK
nEndPos = new long[nCount]; 8J} J;Ga
for(int i=0;i<nStartPos.length;i++) M4| L
{ lgl/| ^ Uw
nStartPos = input.readLong(); ;XT$rtuX
nEndPos = input.readLong(); r_G`#Z_5F
} !SnpesTn
input.close(); 8Ex0[e
} bTj,5,8i
catch(IOException e){e.printStackTrace ();} eIJQ|p<v
catch(Exception e){e.printStackTrace ();} vJ!t.Vou
} R-ci?7dt3
C}CX n X
R##O9BSI8Z
private void processErrorCode(int nErrorCode) y03l_E,
{ HM/ qB^
System.err.println("Error Code : " + nErrorCode); ;\h'A(
} kDsUKO p
#]rw@c
fOfp.`n
//停止文件下载 FwyPmtBj
public void siteStop() ]l`DR4 =
{ 2bqwnRT}
bStop = true; VrpYBU
for(int i=0;i<nStartPos.length;i++) BtspnVBez
fileSplitterFetch.splitterStop(); q6q=,<T%S
7 UR)4dYA
@:}z\qBM
} piU4%EO
} ,M9'S;&^
//负责部分文件的抓取 I/'>Bn+
**FileSplitterFetch.java R0Qp*&AL
*/ q_!3<.sf
package NetFox; >a,w8^7
|$Td-M^)
QeGU]WU{
import java.io.*; 1z)+P1nH]
import java.net.*; {zw#My
gCmGFQE-f
Y#\e~>K
public class FileSplitterFetch extends Thread { bbz86]AhY
OnG?@sW+4!
p?Y1^/
String sURL; //File URL 3'8~H]<W
long nStartPos; //File Snippet Start Position 1!~9%=%
long nEndPos; //File Snippet End Position |nD`0Rbw
int nThreadID; //Thread's ID IySlu^a
boolean bDownOver = false; //Downing is over }G]]0Oi2
boolean bStop = false; //Stop identical # aC}\
FileAccessI fileAccessI = null; //File Access interface yY}`G-)g~*
1UOFTI2S|
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public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException U9Sp$$L
{ dG1qrh9_-
this.sURL = sURL; Rcu/ @j{O
this.nStartPos = nStart; \!_ >ul
this.nEndPos = nEnd; MD%86m{Sg=
nThreadID = id; Xs4`bbap
fileAccessI = new FileAccessI(sName,nStartPos);//定位 -50|r;a
} nF=h|rN
&`@K/Nf$9
U@H SU%H
public void run() 'i}Q R~pe
{ [xHK^JP 8F
while(nStartPos < nEndPos && !bStop) Q WOd&=:
{ G*ecM`Bl
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DwoO([&I
try{ AtSEKpKc
URL url = new URL(sURL); ^s^X nQhE
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); nfc&.(6x<
httpConnection.setRequestProperty("User-Agent","NetFox"); y8\44WKW
String sProperty = "bytes="+nStartPos+"-"; 5WEF^1
httpConnection.setRequestProperty("RANGE",sProperty); HH^eEh4g
Utility.log(sProperty); %N2=:;f
Hg<]5
^;L;/I[-
InputStream input = httpConnection.getInputStream(); \MnlRBUM,
//logResponseHead(httpConnection); JD.WH|sZ5
?>2k>~xlQ
|@Bl?Bs+
byte[] b = new byte[1024]; (%tKGeb
int nRead; t'^/}=c-
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) 1D6iJ
{ Z O&5C6qa
nStartPos += fileAccessI.write(b,0,nRead); =YR/|9(
//if(nThreadID == 1) `U)~fu/\2M
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); }yUZ(k#
} b*7OIN5h
<Dl7|M
nT:ZSJWM
Utility.log("Thread " + nThreadID + " is over!"); O0e6I&u:
bDownOver = true; <`BUk< uf#
//nPos = fileAccessI.write (b,0,nRead); KATt9ox@
} TwY]c<t
catch(Exception e){e.printStackTrace ();} 4~D?F'o
} d&F8nBIM5
} ~i(X{^,3
~qs97'
4\>Cnc{
//打印回应的头信息 Q1g@FsW&U
public void logResponseHead(HttpURLConnection con) M*|x,K=U
{ WJ8i,7
for(int i=1;;i++) VGkwrS;+I
{ t=5K#SX}
String header=con.getHeaderFieldKey(i); 7&E3d P
if(header!=null) sT|8a
//responseHeaders.put(header,httpConnection.getHeaderField(header)); IF<pT)
Utility.log(header+" : "+con.getHeaderField(header)); Dr&2qX!
else +g%kr~w=
break; Pr9$(6MX
} Iell`;
} K%O%#Kk
_uID3N%
*zJ}=%)f
public void splitterStop() e+j7dmGa
{ .hXxh)F
bStop = true; QYPsqkF*
} YhRES]^
|X0h-kX4
UO>ADRs}
} m!V ?xGKJ
`$7.(.#s
uPhFBD7
/* :>]=YE
**FileAccess.java 4u0=/pfi[
*//文件访问(定位，写) gh#9<
package NetFox; Pd6p)zj
import java.io.*; WL:CBE#
pO[ @2tF
nD6NLV%2x
public class FileAccessI implements Serializable{ wknX\,`Q
S{&,I2aO
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 `{#0C-
RandomAccessFile oSavedFile; zuwlVn
long nPos; F|Pf-.r`t
)%I2#Q"Nt-
[LbUlNq^B@
public FileAccessI() throws IOException |wZcVct~
{ Z_Qs^e$
this("",0); FWNWOU
} 07`hQn)Gc
&Ba` 3V\M
f%<kcM2
public FileAccessI(String sName,long nPos) throws IOException PRg^E4
{ &'Pwz
oSavedFile = new RandomAccessFile(sName,"rw"); 2r4owB?
this.nPos = nPos; h\k@7wgu
oSavedFile.seek(nPos); c 2t<WRG
} @9Rgg9r
F jsnFX;
tJ;<=.n
public synchronized int write(byte[] b,int nStart,int nLen) WBvh<wTw;
{ ge %ytrst
int n = -1; /}t>o* x
try{ (e.?). e
oSavedFile.write(b,nStart,nLen); &@NTedg!
n = nLen; aNs~Uad1U
} }8`W%_Yk
catch(IOException e) [uqe|< :
{ Q8OA{EUtq
e.printStackTrace (); l];w,(u{
} :sDE'o
9$U@h7|Q`
Jr+~'
return n; >>22:JI`
} kV9S+ME
:p%G+q2
Y>W$n9d&G2
} 8`~M$5!
Jas=D
FOz~iS\
/* u_ou,RF
**SiteInfoBean.java S{wR Z|8U
*/ #SyF-QZ[1
package NetFox; S5'ZKk
^C$Oht,cU
}81eef4$S
public class SiteInfoBean { wiHGTaR
8$9Q=M
M uz+j.0
private String sSiteURL; //Site's URL @/jLN
private String sFilePath; //Saved File's Path nIc:<w]
private String sFileName; //Saved File's Name X)6}<A
private int nSplitter; //Count of Splited Downloading File '9d<vWg
[Ume^
ML eo3
public SiteInfoBean() g2)jd[GM
{//nSplitter的缺省值为5 vz$-KT4e^
//default value of nSplitter is 5 YvA@I|..~
this("","","",5); ]:H((rk
} l}w9c`f
RgTm^?Ex
o^Z/~N
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) Q5Yy \M
{ !'m MGxkEb
sSiteURL= sURL; SUGB)vEa
sFilePath = sPath; 6WI-ZEVp&
sFileName = sName; Qg9*mlm`
this.nSplitter = nSpiltter; (h&XtFul}
#WE"nh9f|z
8d4:8}
} 4sJM!9eb[
-o: ifF|
;zq3>A
public String getSSiteURL() itotn!Wb`
{ 3jR>
return sSiteURL; JdYmUM|K/c
} dOG]Yjc
pX 4:WV
,EsPm'`?A/
public void setSSiteURL(String value) b{+7sl
{ U-h'a: K
sSiteURL = value; |aWeo.;c
} *aem5E`c
^lw0} i
3jeB\
public String getSFilePath() ]\TYVv)
{ KH=4A-e,0
return sFilePath; hKx*V"7/#\
} _.}1 Y,Q
:2v^pg|
c qWX*&2_
public void setSFilePath(String value) '>"riEk
{ mHj3ItXUu
sFilePath = value; 6(M^`&fl
} <xn96|$
8,VX%CS#q
xJcM1>cT>
public String getSFileName() yiT)m]E d
{ yW@0Q:
return sFileName; 5Yxs_t4
} &PE/\_xD_
NI<;Lm
&<Iyb}tA?
public void setSFileName(String value) `qXCY^BH2
{ 8?yRa{'"
sFileName = value; WSi`KNX
} :NCY6? [Dz
s8O.yL
OCX>LK!K
public int getNSplitter() J`I^F:y*
{ !PySYY
return nSplitter; LvM;ZfAEv
} 0aWy!d
BI|BfO%F$j
1K&_t
public void setNSplitter(int nCount) N'5AU (
{ @gc|Z]CV
nSplitter = nCount; j Z6]G{
} MJyz0.9c
} {?+dVLa^;
- WEEnwZ
Q`0k=<
/* wO-](3A-8P
**Utility.java {p90
*/ *X%dg$VcV
package NetFox; H Z)an
_x'?igy
U@'F9UB`
public class Utility { HxE`"/~.7k
i!nPiac
Le?yzf
public Utility() SWq5=h
{ s.uw,x
dv7IHUFf
l<DpcLX
} ?7eD<|
;)c 4
//线程睡眠 L_~vPp
public static void sleep(int nSecond) ' K\ $B_
{ d*cAm$
try{ ZC!GKWP2
Thread.sleep(nSecond); <+r<3ZBA
} g~/@`Z2Y
catch(Exception e) $D%[}[2
{ 12olVTuw
e.printStackTrace (); s*3p*zf
} rn8#nQ>QZ%
} Nn:>c<[
:~PzTUz
//日志 cD5^mxd%
public static void log(String sMsg) |to|kU
{ I_aSC4
System.err.println(sMsg); gX'nFGqud
} \v,mr|
%=PGvu
f8AgTw,K8
public static void log(int sMsg) lYq/ n&@_1
{ lk[BS*
System.err.println(sMsg); s9\HjK*+
} n7$21*,
} No(p:Snbo
q33Z.3R
]!mC5Ea
/* +<TnE+>j
**TestMethod.java cy%S5Rz
*/ }b$W+/M\
package NetFox; F,)\\$=,
U%qE=u-
3B^`xnV
public class TestMethod { M[}aQWT$v
^DaP^<V
I<}<!.Bc!
public TestMethod() ?E2$
{ ///xx/weblogic60b2_win.exe F?jFFwim
try{ h+"UK=
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); /t$J<bU
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); ch-.+p3
SiteFileFetch fileFetch = new SiteFileFetch(bean); qVe&nXo
fileFetch.start(); MEled:i
} o 00(\ -eb
catch(Exception e){e.printStackTrace ();} R>CIEL
84|oqwZO
\[CPI`yQe
} C\RJ){dk
'0MH-M
WKDa]({k%
public static void main(String[] args) ,T<q"d7-#
{ #ts;s\!
new TestMethod(); Q[Xh{B
} _ !r]**
} GyP.;$NHa[
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