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)); x&}]8S)
} !40>LpL[
for(int i=0;i<nEndPos.length-1;i++) /zn=AAYb
{ d[ N1zQW
nEndPos = nStartPos[i+1]; L*nK> +
} \bA Yic
nEndPos[nEndPos.length-1] = nFileLength; hlTbCl
} 2z.ot'
} Hvl n>x@
Wboh2:TH:
k4TWfl^}9
//启动子线程 D:)Wr, 26
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; cs9^&N:w[
for(int i=0;i<nStartPos.length;i++) JTlk[c
{ @[$_cGR7
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), {7o#Ve
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), ab0Sx
nStartPos,nEndPos,i); gT+/nSrLV
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); enoj4g7em^
fileSplitterFetch.start(); i;[y!U
} a QH6akH
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), gr=h!'m
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); %x)bZ=An
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", M[uWX=
nEndPos = " + nFileLength); z\YIwrq3*
// fileSplitterFetch[nPos.length-1].start(); +^)v"@,VP
oFY!NMq}:
ON?Y Df
//等待子线程结束 ;"3B,Yj
//int count = 0; jYsAL=oh,*
//是否结束while循环 D}-.<
boolean breakWhile = false; XQ}Zr/f6
Fsx?(?tCMo
|(7}0]BP0
while(!bStop) xQy,1f3s+
{ tAX*CMW
write_nPos(); 'J|2c;M\x
Utility.sleep(500); B.z$0=b
breakWhile = true; %+7]/_JO&
@KG0QHyiU
>}5?`.K~Q*
for(int i=0;i<nStartPos.length;i++) s-i|P
{ xad`-vw
if(!fileSplitterFetch.bDownOver) yPyu)
{ NnZW@ln"|
breakWhile = false; Bd>~F7VWs
break; @Mk`Tl
} [oWkd_dK
} Bqx5N"
if(breakWhile) GQ_KYS{
break; }d$-:l,w
L`NIYH<^
?Ua,ba*
//count++; Tc2.ciU
//if(count>4) Cj5mM[:s
// siteStop(); :<%bAn
} t=_^$M,yr
K^-1M?
w~'xZ?
System.err.println("文件下载结束！"); f|RmAP;X,
} *Cy54Z#
catch(Exception e){e.printStackTrace ();} ^l &lwSRVt
} 6( HF)z
UD I{4+z
n:j'0WW
//获得文件长度 HL)!p8UHJ
public long getFileSize() DA=!AK>
{ ~lj~]j
int nFileLength = -1; 7y=>Wa?T[
try{ E-LkP;
URL url = new URL(siteInfoBean.getSSiteURL()); A_9WSXR
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); f~IJ4T2#N
httpConnection.setRequestProperty("User-Agent","NetFox"); LiJYyp
^:nc'C gP
-@To<<`n
int responseCode=httpConnection.getResponseCode(); qHtQ4_Zn;
if(responseCode>=400) .RQra+up
{ K!|eN_1A
processErrorCode(responseCode); lFBdiIw
return -2; //-2 represent access is error De$AJl
} z*@eQauA
Dc9uq5l
WhPP4 #
String sHeader; A=|XlP$6
j50vPV8m
,GbmL8P7Y
for(int i=1;;i++) !\4x{Wa]
{ \Lx=iKs<
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); Y$'j9bUJ
//Utility.log(in.readLine()); \ovs[&
sHeader=httpConnection.getHeaderFieldKey(i); sqkWQ`Ur
if(sHeader!=null) \i.]-k
{ bzN[*X|
if(sHeader.equals("Content-Length")) V&mkS
{ 6Yai?*.Q
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); 1v@#b@NXM7
break; k %I83,+
} rYUIFPN
} <T2O^
else ]uXJjS f
break; 8PI%Z6
} /A_:`MAZ
} *A-_*A
catch(IOException e){e.printStackTrace ();} A;AQw
catch(Exception e){e.printStackTrace ();} %ms%0%
.Rr^AGA4
@@d_F<Ym[
Utility.log(nFileLength); ]jT}]9Q$
K3&xe(
Om3Ayk}
return nFileLength; IZVP-
} i_qY=*a?y
yT^x0?U
|Xt G9A>
//保存下载信息（文件指针位置） S-t#d7'B
private void write_nPos() 41 F;X{Br
{ Nt>^2Mv
try{ *s6x
output = new DataOutputStream(new FileOutputStream(tmpFile)); RhWQ:l]
output.writeInt(nStartPos.length); *l5?_tF
for(int i=0;i<nStartPos.length;i++) 7x)Pt@c
{ ]b-2:M
// output.writeLong(nPos); +n^M+ea;
output.writeLong(fileSplitterFetch.nStartPos); -()WTdIy
output.writeLong(fileSplitterFetch.nEndPos); VL%. maj
} :a wt7lqv
output.close(); fCt|8,-H
} j~v`q5X
catch(IOException e){e.printStackTrace ();} *)m:u:
catch(Exception e){e.printStackTrace ();} o78u>Oy
} v9(5HY
^O|fw?,
*_D/_Rp7
//读取保存的下载信息（文件指针位置） }`R,C~-|^
private void read_nPos() !Asncc G
{ #XQ/y}(
try{ w8lrpbLh
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); J[lC$X[
int nCount = input.readInt(); 'LgRdtO6
nStartPos = new long[nCount]; 0ix(1`Z
nEndPos = new long[nCount]; t:wBh'K~R8
for(int i=0;i<nStartPos.length;i++) ]V"P &;m
{ P2n8HFi
nStartPos = input.readLong(); wFMH\a
nEndPos = input.readLong(); `gSMb UgF
} %q5dV<X'c
input.close(); KL \>-
} 99yWUC,
catch(IOException e){e.printStackTrace ();} ]_C"A
catch(Exception e){e.printStackTrace ();} ]zx%"SUM
} /2Izj/Q
^E}?YgNp
~'M<S=W
private void processErrorCode(int nErrorCode) ("U<@~
{ JrcbJt
System.err.println("Error Code : " + nErrorCode); b1Vr>:sK47
} 4,y7a=qf3
f*%kHfaXgN
Fz#@[1,
//停止文件下载 >zJHvb)b\
public void siteStop() U["0B8
{ r+#{\~r7T
bStop = true; U7WYS8
for(int i=0;i<nStartPos.length;i++) y[N0P0r l:
fileSplitterFetch.splitterStop(); )rEl{a
kN=&"
,I"T9k-^
} !!\}-r^y%
} h,c*:
//负责部分文件的抓取 @c^ Dl
**FileSplitterFetch.java (dlp5:lQz
*/ =p+n(C/
package NetFox; W&5/1``u\
_X#Rv2a
m%0-3c(
import java.io.*; '0Cp
import java.net.*; WW:G( \`
oC`F1!SfOO
:#:|:q.]
public class FileSplitterFetch extends Thread { G&S2U=KdV%
^PEw#.WG
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String sURL; //File URL xMr,\r'+
long nStartPos; //File Snippet Start Position i q`}c |c
long nEndPos; //File Snippet End Position \3hA_{ w
int nThreadID; //Thread's ID xM%4/QE+
boolean bDownOver = false; //Downing is over ROFZ*@CH<
boolean bStop = false; //Stop identical cWAw-E5
FileAccessI fileAccessI = null; //File Access interface vAX(3
sD3ZZcy|=
y,5qY}P+
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException m*m),mZ"
{ JP8}+
this.sURL = sURL; l.@1]4.
this.nStartPos = nStart; F*P0=DD
this.nEndPos = nEnd; !<M eWo
nThreadID = id; ?=&; A
fileAccessI = new FileAccessI(sName,nStartPos);//定位 ]FCP|Jz
} IV,4BQ$
%)j&/QdzF&
\D|IN'!D
public void run() 9rEBq&
{ D|q~n)TW5
while(nStartPos < nEndPos && !bStop) Z1 Nep!
{ L('1NN2
`=Ip>7T&
Vg'R=+Wb
try{ .?{no}u.
URL url = new URL(sURL); ~kZdep^]
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); [1rQ'FBB^1
httpConnection.setRequestProperty("User-Agent","NetFox"); &D3]O9a0;
String sProperty = "bytes="+nStartPos+"-"; 8R*;8y_
httpConnection.setRequestProperty("RANGE",sProperty); @bg9 }Z%\h
Utility.log(sProperty); !@& 3q|
h~>1-T8
}StzhV{GS
InputStream input = httpConnection.getInputStream(); akvi^]x
//logResponseHead(httpConnection); m]jA(
EL~$7 J
IWE([<i}i[
byte[] b = new byte[1024]; DvH-M3
int nRead; W_B=}lP@x
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) g@#he95 }
{ +RJ{)Nec
nStartPos += fileAccessI.write(b,0,nRead); 0%bCP/
//if(nThreadID == 1) NQqw|3
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); )M0`dy{1
} 5t:Zp\$+`
yX!fj\R
== wX.y\.n
Utility.log("Thread " + nThreadID + " is over!"); \dHqCQ
bDownOver = true; !R@LC
//nPos = fileAccessI.write (b,0,nRead); gC?}1]9c
} ebze_:
catch(Exception e){e.printStackTrace ();} +iC:/CJL
} }T[@G6#
} kx&JY9(&#
ins(RWO
_%Z.Re
//打印回应的头信息 eu5te0{G
public void logResponseHead(HttpURLConnection con) Aits<0
{ h@`Rk
for(int i=1;;i++) O=A R`r#u
{ ^t'mW;C$4
String header=con.getHeaderFieldKey(i); eJoM4v
if(header!=null) p-$C*0{
//responseHeaders.put(header,httpConnection.getHeaderField(header)); z)T-<zWO;
Utility.log(header+" : "+con.getHeaderField(header)); qy|bOl
else cH&)Iz`f
break; -H%v6E%yh
} a{ST4d'T
} (}b~}X9
g!^N#o
y11^q*}
public void splitterStop() 1]If< <
{ oEX,\@+u
bStop = true; i~Tt\UA>
} xCZ_x$bk
P|Aac,nE+^
_&, A
} pwN2Nzski
l`\L@~ln
d.f0OhQ
/* =b%f@x_U1
**FileAccess.java s:_hsmc"
*//文件访问(定位，写) x/<ow4C
package NetFox; mW{;$@PLF"
import java.io.*; N[ =I
JA4Zg*7I
wKpGJ& {
public class FileAccessI implements Serializable{ i6paNHi*
[<=RsD_q~
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 !EIH"`>!
RandomAccessFile oSavedFile; P"NI> HM
long nPos; +jE)kaV%
FJ84'T\~
3}}/,pGSc
public FileAccessI() throws IOException eY3:Nl^
{ ]L~z9)
this("",0); }4>u_)nt
} ^x&x|ckR!
4PVg?
21OfTV-+3
public FileAccessI(String sName,long nPos) throws IOException /K!)}f(6
{ '`upSJ;e
oSavedFile = new RandomAccessFile(sName,"rw"); <l1/lm<#
this.nPos = nPos; `:lcN0n
oSavedFile.seek(nPos); TzC(YWt
} ,P<I<QYu
_ %mm
gp9O%g3'
public synchronized int write(byte[] b,int nStart,int nLen) -}m
{ *wJ$U
int n = -1; (~G*'/)
try{ @zS/J,:v}
oSavedFile.write(b,nStart,nLen); L~ax`i1:"
n = nLen; XF: wsC
} [g}^{ $`
catch(IOException e) v Z10Rb8
{ Fe[6Y<x+:
e.printStackTrace (); ^:?z7m
} q2 7Ac;y
W4 q9pHQ
5V<6_o
return n; 9y\nO)\Tv
} w8D8\`i!"
&K]|{1+
X:Y1g)|K
} `_vPElQXZ#
Vc'p+e|(
[%>*P~6nK
/* xFUD9TM
**SiteInfoBean.java u&p8S#e
*/ ^I/(9KP#
package NetFox; -rsS_[$2
cMi9 Z]
`T[yyOL/
public class SiteInfoBean { [vtDtwL
?bd!JW bg`
<;i&-,
private String sSiteURL; //Site's URL Z2{$FN
private String sFilePath; //Saved File's Path R@WW@ Of
private String sFileName; //Saved File's Name /,7#%D
private int nSplitter; //Count of Splited Downloading File *Iw19o-I
Q\X_JZ
blz#M #
public SiteInfoBean() &h[)nD
{//nSplitter的缺省值为5 G%gdI3h1Z
//default value of nSplitter is 5 ;\"Nekd|
this("","","",5); yzpa\[^
} XXwIp-'
sUF5Yq:9
VII`qbxT
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) P9\y~W
{ qjfv9sU
sSiteURL= sURL; ^ &KH|qRrO
sFilePath = sPath; y3*IF2G
sFileName = sName; N cHCcc
this.nSplitter = nSpiltter; $_ $%L0)5
#euOq
j5Yli6r?3-
} q&ed4{H<
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fR.raI4et
public String getSSiteURL() nb5%a
{ rGH7S!\AM
return sSiteURL; 3I?yRE
} !4F@ !.GG!
Z[+Qf3j}o6
,[m4+6G5
public void setSSiteURL(String value) *=z.H *
{ |q o3 E
sSiteURL = value; hQSJt[8My
} 5}NO~Xd<
Cyv_(Oh?dv
'iYaA-9j
public String getSFilePath() uJ*|SSN~
{ YVY(uq)d
return sFilePath; !oV'
} LY0/\Z"N
etW-gbr
/C<} :R
public void setSFilePath(String value) iEFS>kL8e
{ cNN_KA
sFilePath = value; AMgvk`<f
} ;c~DBJg'|
F7x< V=4{
@7PE&3
public String getSFileName() G`!;RX
{ A&'HlI%J
return sFileName; F0NNS!WP7^
} DA4!-\bt@
`~t$k7wm=
Pb D|7IM
public void setSFileName(String value) I^A01\p
{ ;rta#pRn
sFileName = value; A%M&{S'+|X
} = &aD!nTx
.+AO3~Dg
ldoN!J
public int getNSplitter() ~w%Z Bp
{ =TI|uD6T
return nSplitter; eWx6$_|
} VA'<
bOmM~pD
H+2J.&Ch
public void setNSplitter(int nCount) HNoh B4vt
{ 7]9s_13]
nSplitter = nCount; -ap;Ul?
} 7 -V_)FK2c
} f4T-=` SO
?Ve5}N
J=]w$e ?.P
/* =Jl1D*B*
**Utility.java !c`Q?aGV)
*/ 0\}j[-`pF
package NetFox; R}+/jh2O|
zZh`go02E
M!6bf
public class Utility { TbU9 <mY
Ez1*}
<u($!ATb
public Utility() 9'8oOBqm3%
{ $X&OGTlw^
E.% F/mM
2Nl("e^kJr
} yb**|[By
d`nS0Tf'
//线程睡眠 r@<;
public static void sleep(int nSecond) 6nSk,yE'hE
{ B 9Mwj:)}
try{ $kz5)vj "
Thread.sleep(nSecond); ~O 6~',KD
} K6oXnz}
catch(Exception e) @x J^JcE
{ {:FITF3o
e.printStackTrace (); &Y=NUDt_
} fR[!=-6^f
} 17Gdu[E
S@"=,Xj M
//日志 K;xW/7?
public static void log(String sMsg) sBu"$"]
{ hA\8&pI;
System.err.println(sMsg); FW.dHvNX
} Q#r 0DWo\
/eMZTh*1P
qiF~I0_0
public static void log(int sMsg) t@JPnA7~
{ ?RzT0HRd
System.err.println(sMsg); X9gC2iSs]
} Z "=(uwM
} O.}gG6u5
yEqmB4^-
yaR;
/* ^{K8uN7
**TestMethod.java <d5vVn
*/ I!<v$
package NetFox; Qy/bzO
c_a$g
+l/j6)O`(m
public class TestMethod { S'JeA>L
KE&}*Nf[
qtH&]Suu,
public TestMethod() pz IMj_
{ ///xx/weblogic60b2_win.exe yl 8v&e{
try{ 4F4u1r+
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); `U3
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); Fi/G, [q
SiteFileFetch fileFetch = new SiteFileFetch(bean); |O9=C`G_
fileFetch.start(); U?lu@5 ^Z
} hw'2q9J|
catch(Exception e){e.printStackTrace ();} "qm>z@K
mfN@tMp
rWs5s!l,
} KJ)&(Yx
FVmg&[ .
C|J1x4sb@
public static void main(String[] args) _dBU6U:V
{ h*9o_
new TestMethod(); .>'Z9.Xnk
} 9h(hx7]
} ?BZ][~n-Q
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