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)); 4gC(zJ
} Z8FgxR
for(int i=0;i<nEndPos.length-1;i++) Vm\zLWNB
{ poW%Fzj
nEndPos = nStartPos[i+1]; \By_mw
} 2^ ]^Yc
nEndPos[nEndPos.length-1] = nFileLength; ,'HjL:r
} c`\/]
} p*42 @1,
M>m!\bb%.
EK=0oy[
//启动子线程 Z;a)P.l.>
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; 9%|skTgIqH
for(int i=0;i<nStartPos.length;i++) Qx,#Hj
{ Cy uRj[;B
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), "Zhh>cz
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), rZpsC}C'
nStartPos,nEndPos,i); sV2D:%\K:
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); !9NF@e'&!
fileSplitterFetch.start(); frPQi{u$
} $Ugc:L<h+
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), *9r(lmrfj
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); N[3Y~HX!q
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", N}%AUm/L
nEndPos = " + nFileLength); ,~38IIS>_
// fileSplitterFetch[nPos.length-1].start(); 9y&;6V.'
Ewr2popK
H $Az,-P
//等待子线程结束 Cq/u$G
//int count = 0; WgR%mm^
//是否结束while循环 de2G"'F
boolean breakWhile = false; iOEBjj;C
!y~nsy:&7x
IFew3!{\
while(!bStop) 9-{+U,3)
{ dl8f]y#Q
write_nPos(); 6?%$e$s
Utility.sleep(500); ^.)0O3oC
breakWhile = true; |-{e!&
hy;V~J#
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for(int i=0;i<nStartPos.length;i++) Hs8JJGXWB
{ mD% qDKI
if(!fileSplitterFetch.bDownOver) c-&Q_lB
{ hM!g6\ w
breakWhile = false; 6l2O>V
break; *2-b&PQR{
} 9v;[T%%
} rp<~=X
if(breakWhile) (-0d@eqw
break; e<=Nd,v4;
`u_MdB}<x;
CfS;F
//count++; OhN2FkxL
//if(count>4) g}Lm;gs!>
// siteStop(); >r(`4M:
} g.!k>_g`
0Cf'\2
Q.jThP`p
System.err.println("文件下载结束！"); Z-4/xi7
} zBq&/?
catch(Exception e){e.printStackTrace ();} J9tV|0
} #+_=(J
ct=K.m@E%X
J,:;\Xhl
//获得文件长度 !PeSnO
public long getFileSize() 2{BS `f
{ gzvgXZ1q"
int nFileLength = -1; vpT\CjXHZ
try{ <3j`Z1J
URL url = new URL(siteInfoBean.getSSiteURL()); wE<r'
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); `5(F'o
httpConnection.setRequestProperty("User-Agent","NetFox"); 3:#6/@wQ
C .B=E"e
e, 2/3jO
int responseCode=httpConnection.getResponseCode(); x%ccNP0
if(responseCode>=400) U}Puq5[ ?
{ n,s7!z/
processErrorCode(responseCode); :|ahu
return -2; //-2 represent access is error FAc^[~E
} "Vl4=W)u
=E!Y f#p+q
* Wp?0CP
String sHeader; stW G`>X
hP.Km%C)0n
h0dZr-c
for(int i=1;;i++) e9/Mjq\
{ fdwP@6eh
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); ] `q]n
//Utility.log(in.readLine()); m`$Q/SyvG
sHeader=httpConnection.getHeaderFieldKey(i); ]2|fc5G'
if(sHeader!=null) \k"CtzoX
{ !kb:g]X
if(sHeader.equals("Content-Length")) @'M"c q
{ \ %MsG
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); 2cIbX
break; >O rIY
} kQd|qZ=:w
} ;P;c!}:\b
else ]s)Y">6
break; uH'?Ikx"
} UA~ 4O Q]
} %-K5sIz
catch(IOException e){e.printStackTrace ();} -$g~,dIwj
catch(Exception e){e.printStackTrace ();} /|}yf/^9X
:HY =^$\
b$*2bSdv0<
Utility.log(nFileLength); ae@!M
;;Z'd@
kF,ME5%
return nFileLength; 6`7bk35B
} ' i5KRFy-
's5rl
$X/'BCb
//保存下载信息（文件指针位置） 7j=KiiI
private void write_nPos() * ]bB7
{ 1t^9.!$@y
try{ ln8NcAEx
output = new DataOutputStream(new FileOutputStream(tmpFile)); (>x05nh
output.writeInt(nStartPos.length); I''n1v?N
for(int i=0;i<nStartPos.length;i++) qAbmQ{|w
{ z^&$6c_
// output.writeLong(nPos); &s?uMWR
output.writeLong(fileSplitterFetch.nStartPos); ?r8hl.Z>
output.writeLong(fileSplitterFetch.nEndPos); 0pEM0M
} tH *|
output.close(); S|LY U!IWZ
} ^_P?EJ,)`
catch(IOException e){e.printStackTrace ();} cRbA+0m>
catch(Exception e){e.printStackTrace ();} N#e9w3Rli
} 9Sd?,z
tAJ}36aG
^QJJ2jZ
//读取保存的下载信息（文件指针位置） +s8R]3NJ_H
private void read_nPos() Xfqin4/jC
{ 3^y<Db
try{ 2@2d |
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); Dg0rVV6c
int nCount = input.readInt(); cYC^;,C &|
nStartPos = new long[nCount]; MOCcp s*
nEndPos = new long[nCount]; 0wV9Trp
for(int i=0;i<nStartPos.length;i++) g%[:wjV;
{ /w5*R5B{
nStartPos = input.readLong(); Qb/:E}h]$
nEndPos = input.readLong(); 8uH8)
} T=M##`jP%
input.close(); CZeZk
} AgSAjBP
catch(IOException e){e.printStackTrace ();} 62_k`)k
catch(Exception e){e.printStackTrace ();} =*lBJ-L
} CyYr5 Dz
S1y6G/e9
Ny/eYF#
private void processErrorCode(int nErrorCode) v3M$UiN,:
{ 2YW;=n
System.err.println("Error Code : " + nErrorCode); y1PyH
} G'-#99wv.
HZWt>f
D^. c:
//停止文件下载 a*.#Zgy:lK
public void siteStop() 7[qL~BT+
{ qA`@~\qh"
bStop = true; \6?a
for(int i=0;i<nStartPos.length;i++) L;j++^p
fileSplitterFetch.splitterStop(); L2EQ 9i'[
C5TV}Bq\
'&Y_,-i
} c$&({Z{1
} YOGj__:
//负责部分文件的抓取 0\ (:y^X
**FileSplitterFetch.java Gvh"3|u?z
*/ /PTRe5-7
package NetFox; W9tZX5V1
Mkk.8AjC|
L_vl%ii-
import java.io.*; m=^]93+
import java.net.*; $,, PF/N8c
F5/,S
Bh cp=#
public class FileSplitterFetch extends Thread { ZnI15bsDx
id5`YA$
gz[3xH~
String sURL; //File URL J-dB
long nStartPos; //File Snippet Start Position g([:"y?
long nEndPos; //File Snippet End Position !\BZ_guz
int nThreadID; //Thread's ID YJ"D"QD
boolean bDownOver = false; //Downing is over JVy|SA&R
boolean bStop = false; //Stop identical 0<~~0US
FileAccessI fileAccessI = null; //File Access interface ?-mOAHW0q
\DZ.#=d
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public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException r=Lgh#9S
{ U-fxlg|-C
this.sURL = sURL; _r\M}lDh*
this.nStartPos = nStart; QNU~G3
this.nEndPos = nEnd; Sm4BZF~!B
nThreadID = id; ]gcOMC
fileAccessI = new FileAccessI(sName,nStartPos);//定位 \2a;z<(
} 8/dMvAB1So
s[0`
_Wg}#r
public void run() 4^2>KC_
{ Q9O_>mZy
while(nStartPos < nEndPos && !bStop) lm;hW&O9
{ Po@;PR=
=r ^_D=
|R@T`dW
try{ U[?_|=~7
URL url = new URL(sURL); h^tCF=S
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); DWKQ>X6
httpConnection.setRequestProperty("User-Agent","NetFox"); *1`X}
String sProperty = "bytes="+nStartPos+"-"; b1 w@toc
httpConnection.setRequestProperty("RANGE",sProperty); 1s=Q~*f~d
Utility.log(sProperty); G)}[!'<rR
jD9u(qAlH
Y&O2;q/B
InputStream input = httpConnection.getInputStream(); /^nIOAeE
//logResponseHead(httpConnection); OR~ui[w
fy"}# 2
C){Q;`M-<
byte[] b = new byte[1024]; Sf*v#?
int nRead; 13#ff
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) MukJ^h*V
{ ZuGd{p$
nStartPos += fileAccessI.write(b,0,nRead); %hYgG;22
//if(nThreadID == 1) '_.qhsS
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); pz['o
} <F0^+Pf/
Vl5>o$G|<.
70R6:
Utility.log("Thread " + nThreadID + " is over!"); =+j3E<w
bDownOver = true; ;HXk'xN
//nPos = fileAccessI.write (b,0,nRead); 0!dNW,NfJ
} o6O-\d7^M
catch(Exception e){e.printStackTrace ();} k"i3$^v8
} \vT~2Y(K
} z&d.YO_W
iVZ}+Ct<"
xE?KJ
//打印回应的头信息 zs#-E_^%M
public void logResponseHead(HttpURLConnection con) e3;D1@
{ \Yr*x7!
for(int i=1;;i++) d%'#-w'
{ B0Wf$ s^7t
String header=con.getHeaderFieldKey(i); v~L\[&|_
if(header!=null) FJ~d&L\l
//responseHeaders.put(header,httpConnection.getHeaderField(header)); /&#y-D_
Utility.log(header+" : "+con.getHeaderField(header)); I{(!h90
else lgU!D |v
break; `3T=z{HR9g
} *GE6zGdN
} }UW*[dCf>C
?{f6su@rW
o1(;"5MM
public void splitterStop() Wds>'zzS
{ c 1F^Gj!8
bStop = true; K& ^qn&
} lUEbxN
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"crR{OjE"
} T/P\j0hR
q\o#<'F1J
/OztkThx=
/* iiq `:G
**FileAccess.java :wIA.1bK}
*//文件访问(定位，写) MZh.Xo
package NetFox; 1 gjaTPwY
import java.io.*; %@a;q?/?Nd
,ZJ}X 9$<
~&)\8@2
public class FileAccessI implements Serializable{ Ln,<|,fZN
X^eyrqv
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 Ljz)%y[s
RandomAccessFile oSavedFile; iw,uwh|L
long nPos; PkDt-]G.
'W_NRt:
nb/q!8
public FileAccessI() throws IOException #0<pRDXj
{ 2PSExK57
this("",0); j "<?9/r
} &EV%g6
sX~E ~$_g
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public FileAccessI(String sName,long nPos) throws IOException _9lMa7i
{ ^\gb|LEnK
oSavedFile = new RandomAccessFile(sName,"rw"); Cu#n5SF*
this.nPos = nPos; ?{TWsuP7
oSavedFile.seek(nPos); \2y/:
} ,V9qiu=m
uZn_*_J!
j_90iP^5:
public synchronized int write(byte[] b,int nStart,int nLen) Zb1GR5MB`k
{ EX{%CPp7}
int n = -1; (}X5*BB&
try{ !u]@Ru34
oSavedFile.write(b,nStart,nLen); vOlfyH>
n = nLen; 2K>1,[C'Z
} Ql5bjlQdO
catch(IOException e) o i'iZX
{ ),N,!15j,
e.printStackTrace (); %W D^0U|
} Z]b;%:>=
^oPFLez56
_=I1
return n; 'hr_g* i
} M%ecWr!tj
!8UIyw
+C!GV.q[
} QYo04`Rl
[&99#7B
x@43ZH_
/* y$7Ys:R~
**SiteInfoBean.java %_s)Gw&sq
*/ <MG&3L.[
package NetFox; kNWTM%u9
'M6+(`x
bI0xI[#Q
public class SiteInfoBean { }F{s\qUt
Ox J0."
IWv5UmjN
private String sSiteURL; //Site's URL #w|v.35%?
private String sFilePath; //Saved File's Path )=GPhC/sw
private String sFileName; //Saved File's Name #^VZJ:2=|
private int nSplitter; //Count of Splited Downloading File @*vVc`;
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~vDa2D<9%
public SiteInfoBean() {c)\}s(}F
{//nSplitter的缺省值为5 V $I8iVGL
//default value of nSplitter is 5 %( 7##f_
this("","","",5); 9oc_*V0<
} If'2 m_
DQ+6VPc^o
\l(J6Tu
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) 8zeeC eIU
{ >6Uc|D
sSiteURL= sURL; L,A+"
sFilePath = sPath; -'qVnu
sFileName = sName; J(}PvkA
this.nSplitter = nSpiltter; \VhG'd3k
|qe;+)0>K
_(g0$vRP~
} ~-vCY
AmIW$(Ce
E'4Psx9: =
public String getSSiteURL() 4#>Z.sf
{ ?u:`?(\
return sSiteURL; L~/,;PHN
} f$:Y'$Z1
5B)&;[
39O rY
public void setSSiteURL(String value) G8vDy1`q6
{ G 3U[)("
sSiteURL = value; b%MZfaU
} /v9qrZ$$
R/"f
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public String getSFilePath() bj@sci(1?
{ ^X{U7?x
return sFilePath; `>UUdv{C
} >z%YKdq
}I uqB*g[t
}&/>v' G
public void setSFilePath(String value) nxhlTf>3
{ :y7K3:d3
sFilePath = value; P9 HKev?y
} M7?ktK9`ma
{E%c%zzQ
IH=$ wc
public String getSFileName() XcT!4xG0
{ DqWy@7 a
return sFileName; C~4SPCU
} E0RqY3
{Ni]S$7
Ojz'p5d`>
public void setSFileName(String value) 3m75mny
{ Nzgi)xX0HX
sFileName = value; ?xv."I%
} rK'Lvt@w
KwHN c\\
kCD]&
public int getNSplitter() #&)H&H}
{ pW.WJ`Rk
return nSplitter; octQ[QXo#
} 7~+Fec`Ut*
mvH8hvD9
?3K~4-!?/
public void setNSplitter(int nCount) $\*Z
{ glCpA$;VPu
nSplitter = nCount; az![u)
} }=v4(M`%
} l4i51S"
ppn 8
<QvVPE}z
/* RuYIG?J=/
**Utility.java 67&IaDts
*/ I)1ih
package NetFox; Mj1f;$
:(ql=+vDb4
D$4GNeB+#
public class Utility { 'z,kxra|n
\5&Mg81
R98YGW_ dT
public Utility() ^@8XJ[C,_
{ `},:dDHI
:k?`gm$
;/kd.Q
} @k;65'"Q
VD&wO'U
//线程睡眠 @yb'h`f]
public static void sleep(int nSecond) M2ex 3m
{ G{6@]72
try{ )jl@hnA
Thread.sleep(nSecond); TYD( 6N
} !m:WoQ/
catch(Exception e) ;"IWm<]h;-
{ Uv[a ~'
e.printStackTrace (); ($`IHKF1.l
} _Ycz@Jn
} ;taZixOH
1@{ov!YB]
//日志 d+)LK~
public static void log(String sMsg) ~l:Cj*6x8
{ ssQ1u.x9
System.err.println(sMsg); 3<<wHK;)
} 9^g8VlQdT
sx azl]
!VIxEu^ke
public static void log(int sMsg) }iDRlE,
{ C ibfuR
System.err.println(sMsg); Dti-*LB1
} |)To 0Z
} MkFWZ9c3
3HXeBW
V<|N}8{Z2a
/* pSC{0Y$g
**TestMethod.java ~rO&Y{aG#
*/ r6\g#}
package NetFox; DZL(G [
2|\mBP`ok
I`XOvSO
public class TestMethod { -"ZNkC=
V^FM-bg%9
)G/=3;!
public TestMethod() ESoqmCJjb:
{ ///xx/weblogic60b2_win.exe i#YDdz
try{ <H]PP6_g:
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); fhZwYx&t
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); \mu';[gLd
SiteFileFetch fileFetch = new SiteFileFetch(bean); vM5I2C3_>!
fileFetch.start(); p&Nav,9x
} +&"W:Le:
catch(Exception e){e.printStackTrace ();} &u|t{C#0
=.S2gO >
2u_=i$xW
} gYbvCs8O!
_5n2'\] H`
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public static void main(String[] args) rMWvW(@@D
{ o/,%rA4
new TestMethod(); 74 ptd,
} 0P$19TN
} XdIno}pN
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