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)); *Ddi(`
} [ 7g><
for(int i=0;i<nEndPos.length-1;i++) >%u@R3PH]
{ AotCX7T2T
nEndPos = nStartPos[i+1]; #.H}r6jqs
} /'ZKST4
nEndPos[nEndPos.length-1] = nFileLength; ow/U
} \8{\;L C
} 1c$vLo832
J/vK6cO\
nq1 'F
//启动子线程 V7EQ4Om:It
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; TN\|fzj
for(int i=0;i<nStartPos.length;i++) R:M,tL-l
{ V,Q4n%h1.
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 6kN:*
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), 0Qnd6mb
nStartPos,nEndPos,i); \9`#]#1bx5
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); -U>y
fileSplitterFetch.start(); 7/aOsW"6
} 1yMr~Fo
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 7VAJJv3
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); b5<okICD
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", ~Wei|,w'<
nEndPos = " + nFileLength); /`3#4=5-
// fileSplitterFetch[nPos.length-1].start(); FQk!d$BG
?{6s58Q{
I`T1Pll
//等待子线程结束 BJk Z2=
//int count = 0; zU&L.+
//是否结束while循环 {e"dm5
boolean breakWhile = false; (5a1P;_Y
rQb7?O@-
-R b{^/
while(!bStop) Y%@hbUc}x9
{ eVJ^\z:4
write_nPos(); @}&_Dvf
Utility.sleep(500); ml0*1Dw
breakWhile = true; Z.1> kZ
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v7,$7@$:\
for(int i=0;i<nStartPos.length;i++) 6~xBi(m`
{ Ls}7VKl'
if(!fileSplitterFetch.bDownOver) qtMD CXZ^n
{ PyBD
breakWhile = false; hr/o<#OW
break; r|eZv<6
} @kxel`,$e
} IeP WOpj3
if(breakWhile) TB!(('
break; *2e!M^K<
}r%X`i|
O"Q7Rx
//count++; sOpep
//if(count>4) <%P2qgz5
// siteStop(); D+RiM~LH8
} xr%#dVk
Ln!A:dP}c-
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System.err.println("文件下载结束！"); G^;>8r
} KOhA)
catch(Exception e){e.printStackTrace ();} fuMJdAuY7d
} Pw[g
!)pdamdA
O9"/ kmB
//获得文件长度 k~.&j"K
public long getFileSize() [{ ~TcT
{ t9cl"F=
int nFileLength = -1; =0
try{ ~ G6"3"
URL url = new URL(siteInfoBean.getSSiteURL()); .iHn5SGA
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); >V$ Gx>I
httpConnection.setRequestProperty("User-Agent","NetFox"); ])}]/Qw
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}H"kU2l
int responseCode=httpConnection.getResponseCode(); eE@&ze>X
if(responseCode>=400) }4//@J?:
{ g(|{')8?d
processErrorCode(responseCode); T~4N+fK
return -2; //-2 represent access is error Qk1xUE
} hA1-){aw3q
.(CP. d
/i]y$^
String sHeader; ,9D+brm
Qf$|_&|
x@Hd^xH`
for(int i=1;;i++) .2) =vf'd
{ 04U")-\O
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); N<(.%<!
//Utility.log(in.readLine()); tjT>VwqH
sHeader=httpConnection.getHeaderFieldKey(i); [U/(<?F{(
if(sHeader!=null) ._O
{ 3?n>yS
if(sHeader.equals("Content-Length")) w= P9FxB
{ L+}n@B
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); Iw<i@=V
break; tptN6Isuh
} OTDg5:>
} H1n1-!%d
else NMOut@
break; QPtGdd
} }g7]?Ee
} n\z,/'d"
catch(IOException e){e.printStackTrace ();} Z|"p*5O,
catch(Exception e){e.printStackTrace ();} !> }.~[M
,#?uJTLH
T"7~AbgNU
Utility.log(nFileLength); $(e#aHB
X;v$5UKU
'6y}ZE[
return nFileLength; mtz#}qD66
} YH&bD16c3
3jB$2:#
YuZ"s55zU{
//保存下载信息（文件指针位置） 3psU?8(
private void write_nPos() Z_1U9+,
{ 7\FXz'hA
try{ V-'K6mn;
output = new DataOutputStream(new FileOutputStream(tmpFile)); fjk\L\1
output.writeInt(nStartPos.length); W6H,6v
for(int i=0;i<nStartPos.length;i++) l<0}l^C.
{ X4l@woh%
// output.writeLong(nPos); ';Zi@f"
output.writeLong(fileSplitterFetch.nStartPos); ~vlype3/EF
output.writeLong(fileSplitterFetch.nEndPos); |waIpB(
} $Iv2j">3)
output.close(); W"^wnGa@a
} Tou/5?#%e
catch(IOException e){e.printStackTrace ();} ]$b[`g&
catch(Exception e){e.printStackTrace ();} b306&ZVEk
} 6`vC1PK^
M" ^PW,k
./Q,
//读取保存的下载信息（文件指针位置） ib{-A&
private void read_nPos() N_:qRpp6i
{ bwiPS1+);
try{ EBz}|GY;
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); [(1c<b2r
int nCount = input.readInt(); \%^%wXfp
nStartPos = new long[nCount]; ]BR,M4
nEndPos = new long[nCount]; U!U$x74D5
for(int i=0;i<nStartPos.length;i++) sBrI}[oyx
{ {ZY+L;eg1
nStartPos = input.readLong(); P) 3mX.(}
nEndPos = input.readLong(); .`>y@p!
} J{^RkGF
input.close(); E4m`
} ,|&9M^
catch(IOException e){e.printStackTrace ();} A\8}|r(>9E
catch(Exception e){e.printStackTrace ();} K2%w0ohC
} ,^#yo6-
|$5[(6T|
9]q:[zm^
private void processErrorCode(int nErrorCode) o sKKt?^?
{ a!O0,y
System.err.println("Error Code : " + nErrorCode); 5mb]Q)f9-
} x c{hC4^V
[l,Ei?
3}e%[AKh
//停止文件下载 &x3VCsC\|
public void siteStop() w^t/9Nasi
{ XQw>EZdj_N
bStop = true; eq UME
for(int i=0;i<nStartPos.length;i++) h:9Zt0,
fileSplitterFetch.splitterStop(); #8)*1?
;Iq/l%vX
l+V>]?j
} K4kMM*D
} ,G)r=$XU
//负责部分文件的抓取 o}ZdTf=
**FileSplitterFetch.java 812$`5l
*/ t.;LnrY
package NetFox; ~?(N
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7Hs%Cc"
import java.io.*; EY tQw(!Q
import java.net.*; fk&8]tK4
^pUHKXihD
&Y }N|q-
public class FileSplitterFetch extends Thread { irfp!(r
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String sURL; //File URL ;3@cy|\:
long nStartPos; //File Snippet Start Position (SvWvm
long nEndPos; //File Snippet End Position {E@Lft-
int nThreadID; //Thread's ID A,a.8!*}vd
boolean bDownOver = false; //Downing is over S_Wrw z
boolean bStop = false; //Stop identical ,N)/w1?I
FileAccessI fileAccessI = null; //File Access interface @H=:)*;
x@[rms
MjU6/pO}L
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException .hifsB~
{ Om5Y|v"*
this.sURL = sURL; s=;uc]9g
this.nStartPos = nStart; w 47tgPPk
this.nEndPos = nEnd; n^g|Ja
nThreadID = id; (=om,g}
fileAccessI = new FileAccessI(sName,nStartPos);//定位 _WRFsDZ'
} B\XKw'
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k=jk`c{<[
public void run() r8xv#r1
{ Y/*mUS[oa
while(nStartPos < nEndPos && !bStop) $69oV:
{ =o$sxb E(
ye,>A.
R21b!Pd\
try{ Kkm>e{0)AY
URL url = new URL(sURL); >7QvK3S4%
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); =Lf,?"S
httpConnection.setRequestProperty("User-Agent","NetFox"); XzEc2)0'v
String sProperty = "bytes="+nStartPos+"-"; 7Mg=b%IYs
httpConnection.setRequestProperty("RANGE",sProperty); ci?qT,&
Utility.log(sProperty); 6V7B;tB
%yv<y+yP~
]d! UJ&<?
InputStream input = httpConnection.getInputStream(); SMpH._VFeE
//logResponseHead(httpConnection); gMzcTmbc8
zdYy^8V|z
=\H!GT
byte[] b = new byte[1024]; ,Y/ g2 4R
int nRead; !:q/Ye3.
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) t%E!o0+8Z
{ sTn<#l6
nStartPos += fileAccessI.write(b,0,nRead); 0.8 2kl
//if(nThreadID == 1) }&wUr>=
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); &E.^jR~*
} ewctkI$,5
tFp Ygff<
s~5[![1 K
Utility.log("Thread " + nThreadID + " is over!"); x-^`~p
bDownOver = true; XovRg,
//nPos = fileAccessI.write (b,0,nRead); YS/Yd[ e
} nU7>uU
catch(Exception e){e.printStackTrace ();} v>Q#B
} i3@)W4{
} ~a ]+#D
x|pg"v&[
_({hc+9p
//打印回应的头信息 {xXsBh Y
public void logResponseHead(HttpURLConnection con) >n'o*gZM
{ 1H6<[iHW
for(int i=1;;i++) "@iK' c^
{ :bwjJ}F
String header=con.getHeaderFieldKey(i); y1dDO2mA
if(header!=null) n*[XR`r}
//responseHeaders.put(header,httpConnection.getHeaderField(header)); ChGYTn`X
Utility.log(header+" : "+con.getHeaderField(header)); fF7bBE)L/|
else `d5%.N
break; 1Q<^8N)pf
} )u[emv$
} A kC1z73<
$4h5rC g0
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public void splitterStop() PQ5QA61
{ }dgfqq
bStop = true; 4T|b Cs?e
} kmP]SO?tx
>=:&D)m"
"s0)rqf<
} 2$+bJJM
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v%+:/m1
/* Br1&8L-|%
**FileAccess.java O}-jCW;K
*//文件访问(定位，写) &Sw%<N*r
package NetFox; u0|8Tgf
import java.io.*; }B\a<0L/
g{OwuAC_
gQWa24
public class FileAccessI implements Serializable{ $'BSH4~|.
Dfg2`l
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 X[]m _@v
RandomAccessFile oSavedFile; Mo?~_|}
long nPos; n}F&1Z
3!XjtVhK?I
$q6BP'7
public FileAccessI() throws IOException /uPcXq:L~
{ ?Y-%'J(
this("",0); LlX{#R
} eKE#Yr d=x
xjfV?B'Y}V
:W!7mna
public FileAccessI(String sName,long nPos) throws IOException ]m g)Q:d,
{ G&D7a/G\
oSavedFile = new RandomAccessFile(sName,"rw"); +)!YrKuu
this.nPos = nPos; Q sZx) bO
oSavedFile.seek(nPos); dP#|$1
} ub^h&=\S
q)X$^oE!6
OK[T3/v,
public synchronized int write(byte[] b,int nStart,int nLen) ^t` k0<
{ -lbm* -(
int n = -1; XG{{ 2f
try{ $$|rrG
oSavedFile.write(b,nStart,nLen); qLn/2
n = nLen; +T|JK7
} [ey:e6,T9
catch(IOException e) |'P]GK
{ SQBa;hvgM
e.printStackTrace (); &]"
} sGyeb5c
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G_;)a]v8)
return n; UW N*j_9i
} D>/0v8
d"}k! 0m
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} 6IBgt!=,
jF ^~p9z
D^yRaP*|7
/* EN$2,qf
**SiteInfoBean.java +o\:d1y
*/ [B+yyBtx
package NetFox; U{7w#>V .
nxUJN1b!N
xbdN0MAU
public class SiteInfoBean { {@eJtF+2
$@z5kwx:P
v*'^r)Q[p
private String sSiteURL; //Site's URL .<jr0,i
private String sFilePath; //Saved File's Path o)Iff)m$
private String sFileName; //Saved File's Name /xsF90c\h
private int nSplitter; //Count of Splited Downloading File d74d/l1*{
n!YKz"$
8J:}%DaxL
public SiteInfoBean() @G8lr
{//nSplitter的缺省值为5 kDEPs$^
//default value of nSplitter is 5 GR&z,
this("","","",5); -8; 7Sp1
} 0t Fkd
8K.R=
?{/4b:ua
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) 6VS4y-N
{ TT2d81I3m
sSiteURL= sURL; ti5mIW\
sFilePath = sPath; s%qF/70'
sFileName = sName; uD}2<$PP
this.nSplitter = nSpiltter; k`So -e-
0+?7EL~
/I1h2E
} u$>4F|=T
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6ys &zy
public String getSSiteURL() mtJ9nC
{ fa++MNf}3
return sSiteURL; ZjgsR|i
} W }8'Pf
).Fpgxs
I/a/)No
public void setSSiteURL(String value) +aJ>rR
{ ,VCyG:dw
sSiteURL = value; v9:9E|,U+
} ur3(HL
kddZZA3`
q#T/
public String getSFilePath() d*jMZ%@uS
{ OHeT,@(mh
return sFilePath; v16JgycM
} Q?nN!eT
*G{^|z
X#*JWQO=
public void setSFilePath(String value) B.dH(um
{ ex::m&
sFilePath = value; =osv3>&q
} +?:7O=Y
z`!XhU
%K>,xiD)
public String getSFileName() }])oM|fgO
{ XiL~TCkx4
return sFileName; |2RC#]/-Y
} ,eTUhK
I(V!Mv8j
t; 4]cg:_
public void setSFileName(String value) ?)kGA$m#
{ i(AT8Bo2
sFileName = value; _JHd9)[
} =h0,?]z
<~6h|F8
cl]Mi "3_
public int getNSplitter() 5_- (<B
{ v*r7Zz6l
return nSplitter; ToJ$A`_!`
} z.kvX+7'
(BTVD,G
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public void setNSplitter(int nCount) #:[t^}
{ qv]}$WU
nSplitter = nCount; vgsJeV`}I
} V!lZ\)
} g]4(g<:O
>Db;yC&
Ov-icDMm
/* OW3sS+y
**Utility.java w2 a1mU/
*/ >4#)r8;dx
package NetFox; Y0x%sz5
5Ow[~p"l<
vRs,zL$W
public class Utility { TygW0b 1
8n'B6hi
:c8&N-`
public Utility() E^vJ@O
{ \#Pfj&*
.}O[dR
_a6[{_Pc
} ~yH?=:>U
=p*]Az
//线程睡眠 AS =?@2 q
public static void sleep(int nSecond) ^>jwh
{ .?R!DYC`
try{ jz qyk^X
Thread.sleep(nSecond); 7]blrN]
} 4)A#2
catch(Exception e) ,Wk?I%>
{ ]j`c]2EuP
e.printStackTrace (); ~:Ll&29i
} SKkUU^\#R`
} j`~Ms>
kQEy#JQmB
//日志 tasUZ#\6
public static void log(String sMsg) BW 4%l
{ 9{ >Ui
System.err.println(sMsg); ^pQCNKLBY
} y#U+c*LB
D;;!ODX$?
gBC@38|6)
public static void log(int sMsg) ,.OERw
{ G+X Sfr
System.err.println(sMsg); xlA$:M&
} P} 0%-JC
} v":x4!kdX
b:tob0TB
Zc W:6po>
/* BT}!W`
**TestMethod.java 3E!|<q$z
*/ 1Cv-
package NetFox; ?u" 4@
mF,Y?ax
K`u(/kz/<
public class TestMethod { `HZ;NRr
|}(`kW
FaDjLo2'o
public TestMethod() mP0yk|
{ ///xx/weblogic60b2_win.exe m^ tFi7c
try{ y:~ZLTAv
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); C|}iCB
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); -"=U?>(
SiteFileFetch fileFetch = new SiteFileFetch(bean); `f*Q$Ulqx
fileFetch.start(); #a'Ex=%rM
} v(ZYS']d2
catch(Exception e){e.printStackTrace ();} tjdaaN#,V
L?WFmn
gG*X^Uo
} ZWc]$H?
ykV 5
j g8fU
public static void main(String[] args) 57umx`m
{ jRJn+
new TestMethod(); 0n;< ge&~R
} ;"dV"W
} ]G5w6&d
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