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)); E0RqY3
} {Ni]S$7
for(int i=0;i<nEndPos.length-1;i++) 4o M~
{ Lqxhy s
nEndPos = nStartPos[i+1]; vrb@::sy0T
} 1_S]t[?I/
nEndPos[nEndPos.length-1] = nFileLength; nZnqXclzxn
} TO89;O
} V~*>/2+
(U#,;
fx+_;y
//启动子线程 KF#^MEw%
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; I1m[M?
for(int i=0;i<nStartPos.length;i++) RK-bsf
{ dQSO8Jf
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), g]Y%c73
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), k%gj
nStartPos,nEndPos,i); TaSS) n
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); c&wg`1{Hal
fileSplitterFetch.start(); 4GI3|{
} ~vt*%GN3
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), n.c0G`
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); eik_w(xPT
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", bvh#Q_
nEndPos = " + nFileLength); }v}F8}4
// fileSplitterFetch[nPos.length-1].start(); ``<#F3
zZPWE"u}
Q/3*65
//等待子线程结束 5B|.cOE
//int count = 0; sAU%:W{
//是否结束while循环 &'i_A%V
boolean breakWhile = false; [- 92]
3.#L
#*pB"L
while(!bStop) 'kj q C
{ :k?`gm$
write_nPos(); V H`_
Utility.sleep(500); ZKrK>X
breakWhile = true; jj2=|)w$3
kOo Vqu
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for(int i=0;i<nStartPos.length;i++) mK$E&,OkA
{ J \|~k2~
if(!fileSplitterFetch.bDownOver) KRlJKd{
{ 8tSY|ME
breakWhile = false; y _apT<P
break; lHM} E$5
} 0~ nCT&V
} FJH>P\+
if(breakWhile) \EU3i;BNT%
break; ][l5S*CC_
w^8Q~3|7
|sr\SCx
//count++; 9^g8VlQdT
//if(count>4) r3?8nQ$
// siteStop(); +|bmUm<2
} `^{G`es
5'f_~>1Wt
!I1p`_(_7
System.err.println("文件下载结束！"); =7TWzUCO#
} >WZ%Pv*
catch(Exception e){e.printStackTrace ();} (BtU\f#d
} eCKm4l'BZ
Eh;Ia6}
i_m&qy<v
//获得文件长度 V0m1>{
public long getFileSize() wuY-f4
{ :_i1gY)
int nFileLength = -1; xib}E[-l#
try{ JdI*@b2k[
URL url = new URL(siteInfoBean.getSSiteURL()); yn ofDGAf
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); =%I[o=6
httpConnection.setRequestProperty("User-Agent","NetFox"); U%r{{Q1
2X' H^t]7
*0,*F~n
int responseCode=httpConnection.getResponseCode(); "k+ :!D
if(responseCode>=400) :T$}@& -
{ ::02?
processErrorCode(responseCode); ;p*L(8<YI
return -2; //-2 represent access is error @=w)a
} "UD)3_R
0y<9JvN$9
9Oj b~
String sHeader; ,9^ 5
b/\O;o}]
An(gHi;1$
for(int i=1;;i++) v,ecNuy*d
{ ?z M
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); |mG;?>c)
//Utility.log(in.readLine()); 2&'uO'K
sHeader=httpConnection.getHeaderFieldKey(i); jo"+_)]
if(sHeader!=null) BeRs;^r+
{ yg}L,JJU<
if(sHeader.equals("Content-Length")) +e>G V61
{ >h2qam
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); "K>!+<
break; 9{nU\am!\
} X)]>E]X
} !V#*(_+n
else pHVDug3
break; /oe0
} @.cord`
} 5[zr(FuE
catch(IOException e){e.printStackTrace ();} A<H]uQ>
catch(Exception e){e.printStackTrace ();} nUONI+6Z/
S|u5RU8*"|
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Utility.log(nFileLength); ;QuxTmWp^
6k,@+@]t.
24InwR|^
return nFileLength; OdyL j
} A|IPQ=
jyg>'"W
gHUW1E
//保存下载信息（文件指针位置） >@4Ds"Ye"O
private void write_nPos() 056yhB
{ yT3K 2A
try{ i)@vHh82
output = new DataOutputStream(new FileOutputStream(tmpFile)); $aXYtHI
output.writeInt(nStartPos.length); .ZQXY%g
for(int i=0;i<nStartPos.length;i++) FhH*lO&
{ cQh{z8Bf?<
// output.writeLong(nPos); (ce)A,;
output.writeLong(fileSplitterFetch.nStartPos); p(4Ek"
output.writeLong(fileSplitterFetch.nEndPos); G@ybx[_[@
} KYccjX
output.close(); b2F1^]p
} %E,-dw
catch(IOException e){e.printStackTrace ();} $a\X(okx
catch(Exception e){e.printStackTrace ();} .*EP$pc
} (#je0ES
.q]K:}9!\
IP !zg|c,
//读取保存的下载信息（文件指针位置） IMSm
private void read_nPos() %iV\nFal>
{ $\4Or
try{ z5:3.+M5
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); 6x;"T+BSSS
int nCount = input.readInt(); /KvpJ4
nStartPos = new long[nCount]; TKw>eGe
nEndPos = new long[nCount]; Z-U3TrSI
for(int i=0;i<nStartPos.length;i++) Pd 6
{ `n|k+tsC
nStartPos = input.readLong(); IfRrl/!nw
nEndPos = input.readLong(); %ULd_ES^
} ?K}KSJ6_
input.close(); JLyFkV/
} 84Hm PPt
catch(IOException e){e.printStackTrace ();} gJOswN;([
catch(Exception e){e.printStackTrace ();} U8g?
} q|D*H9[ke
CA"`7<,
n |,}
private void processErrorCode(int nErrorCode) 4P24ySy9F
{ y7*^H
System.err.println("Error Code : " + nErrorCode); BYS>"
} 9*|An
NX+ eig</-
;rF:$37^
//停止文件下载 gY=+G6;=<
public void siteStop() )./'RE+(k
{ A,ao2)
bStop = true; Q([g1?F9*
for(int i=0;i<nStartPos.length;i++) v#IZSBvuQK
fileSplitterFetch.splitterStop(); 8>:2li
HoM8V"8B
VxAR,a1+n
} JY>I
} DNM~/Oo
//负责部分文件的抓取 uoBPi[nK
**FileSplitterFetch.java ,%m$_wA$
*/ gD fVY%[Z
package NetFox; :\1&5Pm]
9Bmgz =8
JeCEj=_Z
import java.io.*; X_|} b[b
import java.net.*; %^E>~
`[1]wV5(5@
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public class FileSplitterFetch extends Thread { })w5`?Y
a-DE-V Uls
:Ws3+OI'm3
String sURL; //File URL *KV]MdS
long nStartPos; //File Snippet Start Position qdu:kA:]
long nEndPos; //File Snippet End Position 1-gX=8]]
int nThreadID; //Thread's ID C{S6Ri
boolean bDownOver = false; //Downing is over ma*9O |v^
boolean bStop = false; //Stop identical 4';['
FileAccessI fileAccessI = null; //File Access interface X}bgRzj
<~8W>Y\m
tv|=`~Y
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException )ZmE"
{ +V\NMW4d
this.sURL = sURL; -XY]WWlq
this.nStartPos = nStart; (/Y gcT
this.nEndPos = nEnd; &q` =xF
nThreadID = id; o_$r*Z|HG
fileAccessI = new FileAccessI(sName,nStartPos);//定位 !!K=v7M
} ,|c_l)
\S2'3SDd/
sQH.}W$C
public void run() )d1,}o
{ T@HozZ
while(nStartPos < nEndPos && !bStop) j+ys&pDczm
{ Pr/&p0@aV
CC87<>V
C,z]q$4
try{ 1Q;`<=
URL url = new URL(sURL); )DLK<10
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); y! 1NS
httpConnection.setRequestProperty("User-Agent","NetFox"); rC*nZ*
String sProperty = "bytes="+nStartPos+"-"; (c*Dvpo1
httpConnection.setRequestProperty("RANGE",sProperty); YvHn~gNPhs
Utility.log(sProperty); +yea}uUE
;~q)^.K3
?x/L"h&Kp
InputStream input = httpConnection.getInputStream(); 9VY_gi=vL
//logResponseHead(httpConnection); Zj<T#4?8
hP#&]W3:
JuI,wA
byte[] b = new byte[1024]; ?8nG F%p
int nRead; Tuy*Df
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) +%~g$#tlJo
{ t-Fl"@s
nStartPos += fileAccessI.write(b,0,nRead); wIiT :o
//if(nThreadID == 1) V)Xcn'h
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); zj)[Sntn?
} DpR%s",Q
i!nl%%
%?$"oWmenS
Utility.log("Thread " + nThreadID + " is over!"); JZ7-? o
bDownOver = true; ixkg,
//nPos = fileAccessI.write (b,0,nRead); xMh&C{q
} D.GSl
catch(Exception e){e.printStackTrace ();} =@f;s<v/
} 5VcYdu3
} ']NM_0
O#|E7;
Q&LkST-i
//打印回应的头信息 EkBM>*W
public void logResponseHead(HttpURLConnection con) 3IxT2@H)
{ ),Rj@52l
for(int i=1;;i++) &_6:TqJ
{ f<'C<xnf
String header=con.getHeaderFieldKey(i); 3QVng^"B)
if(header!=null) kgu+q\?
//responseHeaders.put(header,httpConnection.getHeaderField(header)); lb('r"*.
Utility.log(header+" : "+con.getHeaderField(header)); >j?uI6Uw
else G#C)]4[n
break; hU{%x#8}lK
} EKf4f^<
} 3WYW])
m}E$6E^~O
koU.`l.
public void splitterStop() td~3N,S
{ #]'xUgcE9
bStop = true; ^pP 14y*go
} gs3}rW
A.FI] K@
o5R\7}]GE
} )qIK7;
hdB[H8Q
)Fw)&5B!
/* y()( 8L
**FileAccess.java N@$%0!
*//文件访问(定位，写) qGqu/$bh
package NetFox; '9gI=/29D
import java.io.*; 9lxT5Wg
.%A2
+*q@=P,
public class FileAccessI implements Serializable{ /~[R u
JNz0!wi
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 df'g},_
RandomAccessFile oSavedFile; L9@jmh*E
long nPos; UK,P?_e
){:aGGtko
v(O.GhJ@
public FileAccessI() throws IOException ;=OH=+Rl
{ 5PPpX=\
this("",0); oX~CTunP
} (YOgQ)},
I .ty-X]
z"#.o^5
public FileAccessI(String sName,long nPos) throws IOException !)=o,sVA
{ CmOb+:4@K
oSavedFile = new RandomAccessFile(sName,"rw"); Ul Iw&U
this.nPos = nPos; +q$|6?
oSavedFile.seek(nPos); jlBCu(.,_
} }t'^Au`X
fL;p^t u3
ULjzhy+(8
public synchronized int write(byte[] b,int nStart,int nLen) !Xi>{nV
{ d#Ajb
int n = -1; [ UJj*n
try{ )QD}R36Ic
oSavedFile.write(b,nStart,nLen); $ Zr,-
n = nLen; B(LV22#
} z<>_*Lfj
catch(IOException e) ^@2Vh*k
{ #Au&2_O
e.printStackTrace (); mtHz6+
} $@)d9u cd
HV.7IyBA^
3)a29uc:U
return n; (SK5pU
} 1\0@?6`^
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W)cLMGet
} _4$DnQ6&
{6sfa?1j
5nAF=Bj
/* [)~@NN
**SiteInfoBean.java qGCg3u6
*/ /g''-yT7#
package NetFox; V?BVk8D};
Pltju4.:C
H~]o]uAi"
public class SiteInfoBean { qhtAtP>i"
{W<-f?
^ZUgDQduc
private String sSiteURL; //Site's URL ~+yo;[1Yc
private String sFilePath; //Saved File's Path wf%Ep#^6}
private String sFileName; //Saved File's Name A>A'dQ69
private int nSplitter; //Count of Splited Downloading File >r3< O=Z7
5Suc#0y
ot#kU 8f
public SiteInfoBean() 79g>7<vp
{//nSplitter的缺省值为5 0f/!|c
//default value of nSplitter is 5 , % jTXb
this("","","",5); oH0F9*+W
} 3G|fo4g
Y26l,XIV
`0|&T;7
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) L$Ar]O)
{ J6D$ i+
sSiteURL= sURL; 4ZpF1Zc4B
sFilePath = sPath; XF$]KAL0
sFileName = sName; z %E!tB2o
this.nSplitter = nSpiltter; C&N4<2b
g8A{aHb1}
!13 /+ u
} %5?-g[
&W// Ox )f
iGVb.=)
public String getSSiteURL() #-j! ;?
{ B-'BJ|*4I
return sSiteURL; 8k?L{hF|nW
} }AZx/[k |z
*[:CbFE0y
Yka&Kkw
public void setSSiteURL(String value) \ZWmef
{ _J~ta.
sSiteURL = value; ik0Q^^1?Y
} n4T2'e
{0WIDD
4Xk;Qd
public String getSFilePath() F6]!?@
{ 4~YQ\4h=
return sFilePath; Prz+kPP
} :k(t/*Nl3
E/$@ud|l"
LE80`t>M#
public void setSFilePath(String value) *1S.9L
{ *Ne2l`!1m
sFilePath = value; x~Ly$A2p
} Z)T@`B6
?V:]u3
`+Z#*lj|@
public String getSFileName() bK$D lBZ
{ `yXx[deY
return sFileName; dQ`ZrWd_U
} )wzs~Fn/
c&?a,fpb
m3Z}eC8LK
public void setSFileName(String value) X8n/XG~_
{ ::Q);
sFileName = value; Y1aF._Z
} `=$jc4@J
Yn]yd1
P|P fG=
public int getNSplitter() Iki+5
{ ) a\DS yr
return nSplitter; #0<y0uJ(y
} IH5} Az
'7LJuMp$#
~EWfEHf*BJ
public void setNSplitter(int nCount) 5QFXj)hR+4
{ h*%0@
nSplitter = nCount; D)ne *},
} 6O@ ^`T
} mx(%tz^t
2|H91Y2
;n7|.O]*
/* K!D!b'|bb
**Utility.java NRuG?^/}d
*/ qwNKRqT
package NetFox; ZR-s{2sl
]1|Ql*6y,
A;WwS?fyQ
public class Utility { m`\i+
PVS<QN%
)4L%zl7
public Utility() h;ol"
{ *v nxP9<
R4~zL!7;
<X I35\^
} jPYe_y
51ajE2+X&
//线程睡眠 ]D) 'I`
public static void sleep(int nSecond) Q(;B)
{ ss0'GfP
try{ D"x$^6`c}
Thread.sleep(nSecond); kF+}.x%
} s{z~Axup-
catch(Exception e) u_6BHsU
{ 3gI[]4lRH
e.printStackTrace (); 6mF{ImbRbS
} 3b?OW7H
} |:e|~sism
:Hf0Qx6
//日志 g",wkO|
public static void log(String sMsg) :B*vkwT
{ CEX}`I*-
System.err.println(sMsg); /\-2l+y>J
} r}y[r}vk
2%{YYT
2i7i\?<.
public static void log(int sMsg) m,@1LwBH
{ {KU.
System.err.println(sMsg); ,\S pjE
} }l}yn@hYC
} @Ge>i5q
Pn+IJ=0Y
Wiq{wxe
/* &PRx,G5
**TestMethod.java ?y>Y$-v/C
*/ p- "Z'$A`
package NetFox; e'~-`Z9-)
Z@uTkqG)
m1hW<
public class TestMethod { ':!3jZP"m
<DeKs?v
pK6e/eC
public TestMethod() Wa[x`:cT?u
{ ///xx/weblogic60b2_win.exe =mHkXHE~:
try{ 1jH7<%y
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); ]DC;+;8Jc
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); #cj\~T.,,
SiteFileFetch fileFetch = new SiteFileFetch(bean); $5TepH0D
fileFetch.start(); x7P([^i
} MvFM,
catch(Exception e){e.printStackTrace ();} Lh8bQH
)%iRZ\`f
/OQK/ t63
} ~Na=+}.q_
0PnD|]9:
QP6z?j.
public static void main(String[] args) ;YK!EMM4!h
{ AVXX\n\_
new TestMethod(); ="uKWt6n'
} Sao>P[#x
} Qw24/DJK
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