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)); 4[,B;7
} 3R%UPT0>
for(int i=0;i<nEndPos.length-1;i++) "G9'm
{ ;[KriW
nEndPos = nStartPos[i+1]; `o8{qU,*]N
} q X%vRf0
nEndPos[nEndPos.length-1] = nFileLength; n~)HfY
} !\#Wk0Ku
} %:w% o$
yvooM'R
"vOfAo]`
//启动子线程 5u|=;Hz*)
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; u@Cf*VPK
for(int i=0;i<nStartPos.length;i++) iQ|,&K0d]
{ Zp(=[n5
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), yI.}3y{^5
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), nJ*mEB
nStartPos,nEndPos,i); '`]n_$f'
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); De nt?
fileSplitterFetch.start(); Awa|rIM
} |v$%V#Bo
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), -<51CDw,
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); UhSh(E8p>
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", 71l"m^Z3zy
nEndPos = " + nFileLength); 5Hwo)S]r
// fileSplitterFetch[nPos.length-1].start(); VqClM
y^!E "
D,dHP-v
//等待子线程结束 +-aU+7tu
//int count = 0; =l8!VJa
//是否结束while循环 833%H`jQc
boolean breakWhile = false; iL0jpa<}
wAu[pWD'6;
RF4$
while(!bStop) \U!@OX.R'M
{ OJ35En
write_nPos(); d2A wvP
Utility.sleep(500); ^5;vx
breakWhile = true; )ew[ Ak|
&8]#RQy{f
UEEBWzH
for(int i=0;i<nStartPos.length;i++) xz"Z3B
{ ke}Y2sB
if(!fileSplitterFetch.bDownOver) r}oURy,5
{ 4FIV
breakWhile = false; T,WKoB
break; \7,MZt
} \m=-8KpU
} oI_oz0nHk
if(breakWhile) -v;n"Zy1
break; aJ6#=G61l
s-C!uq
kUn2RZ6$#
//count++; llHc=&y#
//if(count>4) 7`blGzP_
// siteStop(); }iua] 4|
} :F7k{~
NV}RRs
).NcLJw_
System.err.println("文件下载结束！"); W&+y(Z-t
} %XJQ0CE<(
catch(Exception e){e.printStackTrace ();} w.J%qWJq
} GSz @rDGY
K,eqD<
6_R\l@a
//获得文件长度 _/,SZ-C#L4
public long getFileSize() v)@,:u)
{ oe(9mYWKa6
int nFileLength = -1; t1e4H=d>
try{ 5c:'>
URL url = new URL(siteInfoBean.getSSiteURL()); IjG5X[@
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); cq*p9c
httpConnection.setRequestProperty("User-Agent","NetFox"); _m9~*
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2Vp>"
int responseCode=httpConnection.getResponseCode(); X,RT<GNNb
if(responseCode>=400) m<FF$pTT
{ ${hyNt
processErrorCode(responseCode); 8W~lU~-
return -2; //-2 represent access is error O9t=lrYV!
} SkiJpMN
7fTxGm
!uWxRpT,7
String sHeader; cVQatm
&sm @
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for(int i=1;;i++) 'FShNY5
{ t|;%DA)fjw
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); XVQL.A7
//Utility.log(in.readLine()); ?^LG hdR
sHeader=httpConnection.getHeaderFieldKey(i); |EF>Y9
if(sHeader!=null) b/}'Vf[
{ <9ma(PFa
if(sHeader.equals("Content-Length")) )K{o<m~WAo
{ <1aa~duT
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); uuu\f*<
break; "_ LkZBW.
} 7{n\yl?
} :3*`IB !
else )fNGB]%
break; C/F@ ]_y
} L)q`D2|'
} @&?a]>L
catch(IOException e){e.printStackTrace ();} W|;nJs:e
catch(Exception e){e.printStackTrace ();} /^w"' '
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3PfiQ|/b
Utility.log(nFileLength); <z^SZ~G
XjX 2[*l
+x(YG(5\w
return nFileLength; @. "q
} c#=&!FRe
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D899gGe
//保存下载信息（文件指针位置） 43KaL(
private void write_nPos() FyCBNtCv
{ e\`wlaP,
try{ [ L
output = new DataOutputStream(new FileOutputStream(tmpFile)); p` $fTgm
output.writeInt(nStartPos.length); Jf2e<?`
for(int i=0;i<nStartPos.length;i++) I?^aCnU
{ &a.']!$^"
// output.writeLong(nPos); !?jK1{E3
output.writeLong(fileSplitterFetch.nStartPos); +<&E3Or
output.writeLong(fileSplitterFetch.nEndPos); nt7|f,_J
} P"b8!k?
output.close(); d>UnJ)V}
} $nj\\,(g
catch(IOException e){e.printStackTrace ();} V]Sgx00;
catch(Exception e){e.printStackTrace ();} >wA+[81[
} vruD U#
-(!uC+BZX
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//读取保存的下载信息（文件指针位置） *t^eNUA
private void read_nPos() NN^QUB
{ \UOm]z
try{ j(sLK &
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); gt'*B5F(
int nCount = input.readInt(); 47KNT7C
nStartPos = new long[nCount]; nh<Z1tMU
nEndPos = new long[nCount]; Q |%-9^
for(int i=0;i<nStartPos.length;i++) Uls+n@\!
{ DE%fF,Hk3
nStartPos = input.readLong(); Y,'%7u
nEndPos = input.readLong(); E${J
} 6.[)`iF+#
input.close(); mB~~_]M N
} =LOk13l\"
catch(IOException e){e.printStackTrace ();} `g--QR
catch(Exception e){e.printStackTrace ();} \6{LR&
} +s ULo
$%Z3;:<Uf-
*#zS^b n
private void processErrorCode(int nErrorCode) / $_M@>
{ tj[c#@[B
System.err.println("Error Code : " + nErrorCode); Apmw6cc
} K U$`!h
SyAo, )j
E4=qh1d
//停止文件下载 Hte[TRbM
public void siteStop() z?4=h Sy
{ Ls1B\Aw_
bStop = true; _B3zRO
for(int i=0;i<nStartPos.length;i++) j1A|D
fileSplitterFetch.splitterStop(); !.*iw k`
9p4y>3
X &D{5~qC
} \9w~pO
} GV5qdD(
//负责部分文件的抓取 4^[ /=J}
**FileSplitterFetch.java +pz}4M`
*/ *jE;9^
package NetFox; h48YDWwy
h,t:]
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import java.io.*; q6REh;$
import java.net.*; CcY7$D
&pL/ @2+
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public class FileSplitterFetch extends Thread { Lc|{aN
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q*bt4,D&Es
String sURL; //File URL tb,9a!?
long nStartPos; //File Snippet Start Position Plfdr~$
long nEndPos; //File Snippet End Position B$?^wo
int nThreadID; //Thread's ID 9,scH65x
boolean bDownOver = false; //Downing is over _w>uI57U
boolean bStop = false; //Stop identical ]ENK8bW
FileAccessI fileAccessI = null; //File Access interface s7l23*Czl
Bd&`Xfebj
VO_dA4C}z
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException gw+eM,Yp
{ CW p#^1F
this.sURL = sURL; H O*YBL
this.nStartPos = nStart; 'mE^5K
this.nEndPos = nEnd; cDIBDC
nThreadID = id; 6e.[,-eU
fileAccessI = new FileAccessI(sName,nStartPos);//定位 @^&7$#jq%
} yQ%"U^.m
nxfoWy
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public void run() Om9jtWk
{ !),t"Ae?>
while(nStartPos < nEndPos && !bStop) to`mnp9Z
{ RgZOt[!.
Hhl-E:"H`
+D`*\d1
try{ to>
URL url = new URL(sURL); -ihiG_f
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); Skxd<gv
httpConnection.setRequestProperty("User-Agent","NetFox"); $(rc/h0/E
String sProperty = "bytes="+nStartPos+"-"; ,[l`zp
httpConnection.setRequestProperty("RANGE",sProperty); p0VUh!
Utility.log(sProperty); Jzex]_:1~
w7 *V^B
.3X Y&6
InputStream input = httpConnection.getInputStream(); A gWPa.'3
//logResponseHead(httpConnection); d:rGyA]
$FX,zC<=
'3Q3lM'lh
byte[] b = new byte[1024]; R\O.e
int nRead; )];aIA$
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) tJ'iX>9I
{ e.8$ga{
nStartPos += fileAccessI.write(b,0,nRead); 7u|B ](FS
//if(nThreadID == 1) >bIF>9T
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); Y3rt5\!
} Ej"u1F14J
:mZYS4L~
HdNnUDb$B
Utility.log("Thread " + nThreadID + " is over!"); qINTCm j
bDownOver = true; izuF !9
//nPos = fileAccessI.write (b,0,nRead); ,b|-rU\
} Ch5+N6c^
catch(Exception e){e.printStackTrace ();} L;/n!k.A
} K0Tg|9
} x?sI;kUw8
+}JM&bfK
J=H)JH3
//打印回应的头信息 GLUUY0
public void logResponseHead(HttpURLConnection con) k\aK?(.RC7
{ ahGT4d`)9
for(int i=1;;i++) Ia4)uV8
{ #fDs[
String header=con.getHeaderFieldKey(i); *C2R`gpBI
if(header!=null) {HrZ4xQnpV
//responseHeaders.put(header,httpConnection.getHeaderField(header)); \TbVS8e^
Utility.log(header+" : "+con.getHeaderField(header)); )(TAT<
else G;1?<3
break; S v`qB'e2
} orfp>B) 0
} H"Dn]$Q\Z
PJ\0JR7a
:Li/=>R^
public void splitterStop() {vVTv SC
{ :]II-$/8
bStop = true; Ed-M7#wY
} D/ Dt
Vw~\H Gs/~
@PSLs*
} m;,xmEp
7wVH8^|
^4pto$#@O:
/* ^?GmrHC)
**FileAccess.java y7lWeBnC
*//文件访问(定位，写) [TTSA2
package NetFox; a`c:`v2o
import java.io.*; $B .Qc!m
|J>WC}g@n
|yY`s6Uq
public class FileAccessI implements Serializable{ NNkP\oh\
uY#TEjGh]
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 ;_+uSalt
RandomAccessFile oSavedFile; qoX@@xr1
long nPos; vHKlLl>*2
<02m%rhuW
lpmJLH.F
public FileAccessI() throws IOException ] d?x$>
{ 55DE\<r
this("",0); yVJ%+d:6
} zT9JBMNE:
4N>>+]MWc
K8[DZ)rO;Z
public FileAccessI(String sName,long nPos) throws IOException 1hmc,c
{ )!W45"l-3M
oSavedFile = new RandomAccessFile(sName,"rw"); CIC[1,
this.nPos = nPos; l67Jl"v
oSavedFile.seek(nPos); diT=x52
} cgT
(<c7<_-H
=|U@
public synchronized int write(byte[] b,int nStart,int nLen) TzG]WsY_
{ e%O0hE
int n = -1; k$i'v:c|:i
try{ =o7}]k7
oSavedFile.write(b,nStart,nLen); 04@cLDX8uB
n = nLen; RHY4P4B<v>
} 9 c3E+
catch(IOException e) AMCyj`Ur
{ L>9R4:g
e.printStackTrace (); T)iW`vZg8
} S4o$t-9l
tkKJh !Q7
{6Au3gt/
return n; rofNZ;nu
} n.}T1q|l
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+[-i%b3q
} 5Fw - d
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[]pN$]+c
/* #f,y&\Xmf
**SiteInfoBean.java _}6q{}jn:c
*/ E/b"RUv}h
package NetFox; Gh( A%x)
t?eH'*>
iThSt72
public class SiteInfoBean { ,FSrn~-j9
MgMD\
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private String sSiteURL; //Site's URL <i. apBH
private String sFilePath; //Saved File's Path {S.>BXX
private String sFileName; //Saved File's Name V"KS[>>f
private int nSplitter; //Count of Splited Downloading File :#t*K6dz
*%FA:Y
y/_XgPfWU
public SiteInfoBean() >{zk qvsQ&
{//nSplitter的缺省值为5 x!<yT?A
//default value of nSplitter is 5 |V,<+BEi
this("","","",5); *f+: <=i
} /bRg?Q
Xl-e !
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public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) Lxl_"kG
{ I:j3sy
sSiteURL= sURL; ~mz%E
sFilePath = sPath; @mQ:7-,~
sFileName = sName; XP?rOOn
this.nSplitter = nSpiltter; ssQ BSbx
2\<.0
1R%1h9I4'
} G;iEo4\?
y'C-[nk
Tny>D0Z#
public String getSSiteURL() Z}6^ve
{ =6nD sibf
return sSiteURL; 5jcte< 5I_
} S=|@L<O
L@Nu/(pB=
LRb,VD:/Y
public void setSSiteURL(String value) qt e>r
{ qOhO qV
sSiteURL = value; {p<Zbm.
} ()T[$.(
a*dQ _
oMH.u^b]fT
public String getSFilePath() ^%T7.1'x
{ io2)1cE&f
return sFilePath; ^eq</5q D
} 3,X/,'
:Ixx<9c.
9"{W,'r&d
public void setSFilePath(String value) j7QX,_Q
{ `TLzVB-j3
sFilePath = value; {tP%epQ
} B2=\2<
/+K?
WN]<q`.
public String getSFileName() 'I}:!Z
{ J4$! 68
return sFileName; .^(/n9|o-
} YPDf Y<?v
v6(E3)J7
256LHY|6
public void setSFileName(String value) y2L#:[8
{ uq3{hB#
sFileName = value; F"+o@9]
} m` AK~O2
/u<nLj1
{}~:&.D
public int getNSplitter() YvL?j
{ Y$>-%KcKeI
return nSplitter; $rB3m~c|
} )eeN1G`rDE
3 fj
dtStTT
public void setNSplitter(int nCount) S^I,Iz+`S'
{ Dr<='Ux[5
nSplitter = nCount; QbFHfA2Ij
} q<vf,D@{ !
} I&yVx8aH}
fK}h"iH+K
-Yi,_#3{
/* d50Vtm\
**Utility.java {2d_"lHBt
*/ $RX'(/
package NetFox; &n2e
"Y:/= Gx
l~:v (R5
public class Utility { (46 {r}_O
:;;E<74e i
DPgm%Xq9(!
public Utility() 6c4&VW
{ 'fV%Z
xg`h40c
NR%Y+8^M
} F?+3%>/A@
{BBw$m,o
//线程睡眠 RrrK*Fk8=
public static void sleep(int nSecond) !\ND(
{ V)M1YZV{
try{ ]:]H:U]p
Thread.sleep(nSecond); +]xFoH
} %hS|68pN6
catch(Exception e) y8Xv~4qQW
{ 5i6 hp;=
e.printStackTrace (); >B -q@D
} AIl4]F5I
} \5 pu|2u
Fe&qwq"
//日志 \p&~,%
public static void log(String sMsg) B1 0+*p(
{ qZk'tRv
System.err.println(sMsg); hi2sec|;<
} klOp ^w
rnFM/GAy
c~,23wP1
public static void log(int sMsg) U'( sn
{ }ucIH@U{
System.err.println(sMsg); c{#yx_)V&
} \0;(VLN'U
} *O$CaAr\s
f|EUqu%E
7v}x?I
/* ;^u*hZN[Up
**TestMethod.java q z&+=d@
*/ u+9<&)X0
package NetFox; bUy,5gk-
K/_9f'^
t@oK~ Nr
public class TestMethod { `iKj
* A|-KKo\
V\~WvV
public TestMethod() oP?YA-#nc
{ ///xx/weblogic60b2_win.exe OKOu`Hz@
try{ yoe}$f4
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); imL_lw^?
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); b;mSQ4+
SiteFileFetch fileFetch = new SiteFileFetch(bean); \uOdALZ
fileFetch.start(); h[tix:
} `s#Hq\C
catch(Exception e){e.printStackTrace ();} m`?MV\^
A1Y7;-D
<G8w[hs
} KU9Z"9#
Rf %HIAVE
hjx)D
public static void main(String[] args) NtGn88='{
{ cS.i
new TestMethod(); E4.SF|=x
} Bvjl-$m!v
} F51.N{'
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