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)); [ QL<&:s&
} cE8 _keR~
for(int i=0;i<nEndPos.length-1;i++) %?{2uMfq-f
{ d-S'y-V?d
nEndPos = nStartPos[i+1]; sB1tce
} PFn[[~5V
nEndPos[nEndPos.length-1] = nFileLength; 6s"bstc{
} *]UEF_
} `LHfAXKN
4sD:J-c
I`}vdX)
//启动子线程 EA{*%9 A
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; $A!h=]
for(int i=0;i<nStartPos.length;i++) v(nQd6;T
{ }T*xT>p^3
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), W;@ae,^
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), R8W44I*R:
nStartPos,nEndPos,i); #di_V"
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); ?~y(--.t;T
fileSplitterFetch.start(); Cot\i\]jv
} (/P&;?j
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), ke6cZV5w
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); YV!V9
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", oX]1>#5UMg
nEndPos = " + nFileLength); 25@j2K(
// fileSplitterFetch[nPos.length-1].start(); L}S4Zz18
?kxWj(D
M{kh=b)V
//等待子线程结束 2]3Jb{8FI>
//int count = 0; \iE9&3Ie
//是否结束while循环 YbBH6RZr
boolean breakWhile = false; \ rWgA
8}E(UsTa
"9T`3cM0
while(!bStop) U4I` xw'
{ A-`J!xj#/
write_nPos(); =Bqa<Js
Utility.sleep(500); ~acK$.#
breakWhile = true; w3cK: C0
"}aM*(l+\
\osQwGPV
for(int i=0;i<nStartPos.length;i++) :Ty*i
{ +&8Ud8Q
if(!fileSplitterFetch.bDownOver) Q>c6ouuJ
{ Y_YIJ@
breakWhile = false; .`#R%4Xl
break; `-YSFQ~O,
} kxf=%<l
} s^@Cq=
if(breakWhile) k_^/
break; _5`S)G{
54DR.>O
X',0MBQ0
//count++; |VEAzY|[#
//if(count>4) [)0k}
// siteStop(); +7OT`e %q
} wupD
2 3w{h d
\ OINzfbr
System.err.println("文件下载结束！"); Afl'-
} mnaD KeA
catch(Exception e){e.printStackTrace ();} ga9:*G!b{)
} =0yJ2[R7Do
Z_WTMs:x!
G")EE#W$}
//获得文件长度 y%l#lz=6
public long getFileSize() ho$%7mc
{ GQBN-Qv
int nFileLength = -1; V/%;:ul.
try{ ryLNMh
URL url = new URL(siteInfoBean.getSSiteURL()); |^{" 2l"j
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); u(`A?H:
httpConnection.setRequestProperty("User-Agent","NetFox"); O!Cu.9}
RteTz_z{
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int responseCode=httpConnection.getResponseCode(); M.^A`
if(responseCode>=400) 80>!qG
{ 2![W N*N>O
processErrorCode(responseCode); $s!meg@s
return -2; //-2 represent access is error y.<Y]m
} %"fKZ
*9wHH-#
Z-!T(:E]
String sHeader; [&s:x,
g$LwXfg
PdBhX
for(int i=1;;i++) L4Y3\4xXO
{ N0hU~|/
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); IomJo
//Utility.log(in.readLine()); #vwXxr
sHeader=httpConnection.getHeaderFieldKey(i); kovzB]
if(sHeader!=null) ;>Qd )'
{ ha~s< I
if(sHeader.equals("Content-Length")) N,$o'\l
{ ?M(Wx
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); 'PbA/MN
break; 6\@, Lb
} DK%eFCo<~
} |%;txD
else X;>} ;LiK
break; X6 cb#s0|
} b<7qmg3
} 3<V!y&a
catch(IOException e){e.printStackTrace ();} #_\~Vrf(#
catch(Exception e){e.printStackTrace ();} A@'W $p?5r
E=trJge
6LQO>k
Utility.log(nFileLength); ZfikNQU9r
C;>Ll~f_
<Rt@z|Zv
return nFileLength; B(dL`]@Xm
} nJg2O@mRJ
Ma#-'J
m/Z_HER^
//保存下载信息（文件指针位置） hh}EDnx
private void write_nPos() NZP,hAUK,
{ B[V=l<J
try{ _,~zy9{,
output = new DataOutputStream(new FileOutputStream(tmpFile)); f'U]Ik;Jy
output.writeInt(nStartPos.length); fTgN2U
for(int i=0;i<nStartPos.length;i++) eO G%6C%a
{ B35f5m7r
// output.writeLong(nPos); $g;xw?~#
output.writeLong(fileSplitterFetch.nStartPos); }iAi`_\0;
output.writeLong(fileSplitterFetch.nEndPos); ~T9[\nU\
} itvdzPO
output.close(); a| cD{d
} rd{(E
catch(IOException e){e.printStackTrace ();} SbivW5|61
catch(Exception e){e.printStackTrace ();} X_l,fu^C#$
} )v0vdAh'b
(5_(s`q.
hBu=40K
//读取保存的下载信息（文件指针位置） ;0gpS y$#
private void read_nPos() mo$*KNW%\
{ k>`X! "
try{ &pz8vWCk
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); yqwr0yDAl
int nCount = input.readInt(); JK`P mp>
nStartPos = new long[nCount]; 5yID%
nEndPos = new long[nCount]; {{,%p#/b
for(int i=0;i<nStartPos.length;i++) )' #(1 ,1k
{ A?zW!'
nStartPos = input.readLong(); CG;D(AWR;
nEndPos = input.readLong(); A>puk2s
} ,V?,I9qf
input.close(); rg~CF<
} Xv:IbM> Qc
catch(IOException e){e.printStackTrace ();} wBET.l'd
catch(Exception e){e.printStackTrace ();} i|mA/ e3b
} nj$K4_
d]]qy
H"l'E9k.&p
private void processErrorCode(int nErrorCode) a{W-+t
{ qT4s*kqr
System.err.println("Error Code : " + nErrorCode); 4{KsCd)
} p%-9T>og
?da3Azp
IpxjP\
//停止文件下载 kZNZ?A<D
public void siteStop() b&1@rE-
{ S)%x22sqf
bStop = true; t/g}cR^Q
for(int i=0;i<nStartPos.length;i++) (1^(V)@
fileSplitterFetch.splitterStop(); |*$_eb
n6f|,D!?
Y<v55m-
} -,&Xp>u\
} 25L{bcng
//负责部分文件的抓取 lLhCk>a
**FileSplitterFetch.java %Y TIS*+0
*/ wah`
package NetFox; "6i9f$N
4SYN$?.Mp
b}:Z(L,\
import java.io.*; (L1`]cp
import java.net.*; W#!\.m`5
\2jY)UrQs
kXWx )v
public class FileSplitterFetch extends Thread { $u :=lA:N
/L.a:Er$
F@BNSs N=
String sURL; //File URL -)@.D>HsOt
long nStartPos; //File Snippet Start Position 6D],275`J
long nEndPos; //File Snippet End Position & \m\QI
int nThreadID; //Thread's ID UL/>t}AG
boolean bDownOver = false; //Downing is over P7b2I=t
boolean bStop = false; //Stop identical ,o)MiR9-[A
FileAccessI fileAccessI = null; //File Access interface ,n*.Yq
5kF5`5+Vj
t>xV]W<
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException iYf4 /1IG,
{ FyEl@ }W
this.sURL = sURL; C6n4OU
this.nStartPos = nStart; SxDE3A-:
this.nEndPos = nEnd; ;Yj}9[p;T
nThreadID = id; TI332,eL
fileAccessI = new FileAccessI(sName,nStartPos);//定位 nCrNZ&P
} Mw~?@Sq
AZa3!e/1
kBzzi^cl
public void run() gT.-Cf{
{ o;.-I[9h]
while(nStartPos < nEndPos && !bStop) }/VHeHd
{ v09f#t$;5
KJd;c.
ZLkJYZk
try{ j{g{`Qa
URL url = new URL(sURL); 61'7b`:(hi
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); ?,j:Y0l.L
httpConnection.setRequestProperty("User-Agent","NetFox"); 1f=L8Dr
String sProperty = "bytes="+nStartPos+"-"; HZT;7<
httpConnection.setRequestProperty("RANGE",sProperty); $spf=t"nh
Utility.log(sProperty); uMI2Wnnc:/
g@Zc'g/XB
(GQy"IuFh
InputStream input = httpConnection.getInputStream(); ?vVkZsU
//logResponseHead(httpConnection); ,"'agg:St
6]Jv3Re'(I
"#7i-?=
byte[] b = new byte[1024]; ;Y"J j
int nRead; 4g 1h:I/
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) +FiV!nRkZ
{ n'ro5D
nStartPos += fileAccessI.write(b,0,nRead); DB0xIP~i,?
//if(nThreadID == 1) Z|W=.RdA;
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); z,9qAts?mh
} &[YG\8sxWa
gvC2\k{
-4Xr5j%o
Utility.log("Thread " + nThreadID + " is over!"); lcr=^
bDownOver = true; )oj`K,#
//nPos = fileAccessI.write (b,0,nRead); <n><A+D
} M(|gfsD
catch(Exception e){e.printStackTrace ();} AKpux,@xB
} s+[=nau('w
} {t7 M
O!g> f
:* 'i\
//打印回应的头信息 [ACYd/
public void logResponseHead(HttpURLConnection con) v zn/waw
{ -b{*8(d<I
for(int i=1;;i++) 8{ep`$(K@
{ O/k4W#
String header=con.getHeaderFieldKey(i); ! >:O3*/
if(header!=null) K)qmJ-Gub
//responseHeaders.put(header,httpConnection.getHeaderField(header)); t~AesHZpk
Utility.log(header+" : "+con.getHeaderField(header)); yaf2+zV*
else b &JPLUr
break; gFKQm(0g2
} VYF4q9
} \R<yja
j.z#fU
-X=f+4j
public void splitterStop() DxYu
{ g9gyWz
bStop = true; b,cvQD
} L$b9|j7
!O5UE
.,c8cq?
} ;7hf'k
rdK.*oT
PQfx0n,
/* v uJ~Lg{
**FileAccess.java }$7Hf+G
*//文件访问(定位，写) {*|yU"
package NetFox; mz#(\p=T
import java.io.*; hE=cgO`QU
%pMW5]H
V=YK3){>A
public class FileAccessI implements Serializable{ 8\yH7H
?FA:K0H?zl
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 %B~`bUHjq
RandomAccessFile oSavedFile; Kg.E~
long nPos; JK1b68n
I[&!\Me[+w
t*DM^.@
public FileAccessI() throws IOException F/!C=nS
{ v7ae^iU
this("",0); U'\\(m|
} =3}+f-6"'
Dk4Wj"LS
ZK13[_@9
public FileAccessI(String sName,long nPos) throws IOException Z?GC+hG`
{ aqMZ%~7
oSavedFile = new RandomAccessFile(sName,"rw"); {ng
this.nPos = nPos; Jjy}m0)#W_
oSavedFile.seek(nPos); ^=tyf&"
} 6sPd")%G
@<};Bo'
-F*j`
public synchronized int write(byte[] b,int nStart,int nLen) 5B51^"
{ &o?pZ(\C
int n = -1; nZ{~@E2
try{ MM97$
oSavedFile.write(b,nStart,nLen); Me8d o; G|
n = nLen; F`-? 3]\3
} t'z]<7
catch(IOException e) #0mn_#-P)
{ 0xPML}|V
e.printStackTrace (); Db2G)63
} >6aCBS?2
9/nL3U@i1
P[Qr[74)
return n; 9 Iw+g]`y*
} :!3P4?a
L\b$1U!i
UP,(zKTA
} '8}\! i&
cd:O@)i
AD8~
/* Y&#<{j':
**SiteInfoBean.java 5Wn6a$^
*/ YKk%lZ.8
package NetFox; ln3.TR*
d 5Il0sG
?"L>jr(
public class SiteInfoBean { 9 /9,[A
r*WdD/r|
x[)S3UJ
private String sSiteURL; //Site's URL =P5SFMPN
private String sFilePath; //Saved File's Path z\;kjI
private String sFileName; //Saved File's Name 2[WQq)\
private int nSplitter; //Count of Splited Downloading File K[ylyQ1
p,xM7V"O)
jSddjs
public SiteInfoBean() s_RYYaM
{//nSplitter的缺省值为5 $+?6U
//default value of nSplitter is 5 0|HhA,u
this("","","",5); D]4?UL
} 9gWQGkql
a5&wS@) ;
{B[i|(xQx
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) b?r0n]
{ %';n9M
sSiteURL= sURL; g:O.$
sFilePath = sPath; 3 \kT#nr
sFileName = sName; `pLp+#1 `R
this.nSplitter = nSpiltter; \0b",|"3
eNXpRvY
u]zb<)'_
} 9%)'QDVGLf
;T/' CD
~kYF/B2*
public String getSSiteURL() RRV&!<l@$
{ X.JB&~/rO
return sSiteURL; l ='lV]
} 2!jbaSH(+
U:`rNHl
| WDX@Q
public void setSSiteURL(String value) #8[,w.X
{ %,>,J`
sSiteURL = value; RI%*5lM8;
} P~?u2,.E[
#ReW#?P%b/
@GGyiK@
public String getSFilePath() ~r!jVK>^
{ $-o39A#
return sFilePath; G"J6X e
} I2zSoQ1P
:CH'Bt4<
{Q4=GrS
public void setSFilePath(String value) J,IOp-
{ ^up*KQ3u\
sFilePath = value; N["(ZSS
} :s8,i$Ex
"i#!
V @8X.R>
public String getSFileName() lMP|$C
{ \f._I+gJ
return sFileName; iPHMyxT+S
} J_`.w
EQ7cK63
OxqP:kM
public void setSFileName(String value) W}(dhgf
{ dedi6Brl
sFileName = value; K_RrSI&>
} :Z&ipd!yY
76c}Rk^
S~m*t i(
public int getNSplitter() s2v\R~T
{ /oWB7l&
return nSplitter; p-ry{"XA
} ]QpR>b=[j
M?]ObIM:5
} 1c5#Ym
public void setNSplitter(int nCount) C?b Mj[$
{ !(+?\+U lE
nSplitter = nCount; GhQ.}@*
} Xst&QKU
} 4CNK ]2
.p0;y3so4
Ws(BouJ
/* iPE-j#|
**Utility.java 0k3^+#J
*/ +y-:(aP
package NetFox; :<nL9y jt
:@Q_oyWE8
p%j@2U
public class Utility { _gU[FUBtJ
Ih"f98lV
^gv)[
public Utility() c L84}1QD
{ ]Y, 7 X
~~h9yvW7&
a)}?rzT]
} :%s9<g;-h_
GT'%HmQI
//线程睡眠 A(<- U|
public static void sleep(int nSecond) >a^H7kp
{ Xr':/Qjf
try{ k9Yr&8B
Thread.sleep(nSecond); Z73 ysn}
} `SOaQ|H
catch(Exception e) ZP?](RV>xg
{ ][TS|\\
e.printStackTrace (); {>5c,L$
} KA.@q AEB
} y*_g1q$
X~W5Z(w(O
//日志 ~|?2<g$gYR
public static void log(String sMsg) UlQ}
{ !74*APPHR
System.err.println(sMsg); 8vnU!r
} VRMlr.T+
WqwD"WX+w
5MiWM2"X\
public static void log(int sMsg) LgB}!OLQ
{ q-p4k`]
System.err.println(sMsg); >Utn[']~
} D|UDLaz~
} <:/V`b3a
>>&~;PG[
[<OMv9(l'o
/* P]INYH
**TestMethod.java !'n+0
*/ Qg1LT8
package NetFox; 2R.YHj
Br-bUoua
J]$%1Y
public class TestMethod { {"s9A&
Y$Fbi2A4
]}C#"Xt
public TestMethod() ./.E=,j
{ ///xx/weblogic60b2_win.exe wxvt:==
try{ vO <;Gnh~
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); zoO>N'b3)
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); @bS>XWI>
SiteFileFetch fileFetch = new SiteFileFetch(bean); ~H?RHYP~
fileFetch.start(); =OhhMAn
} gM_Z/$
catch(Exception e){e.printStackTrace ();} Qb9) 1
SyTcp?H
h]G}E9\l
} m;8_A|$A
cLJ|VD7
W~R_- ]k@g
public static void main(String[] args) 2<YHo{0BLS
{ lD\lFN(:
new TestMethod(); #& Rx(
} rHN>fySn7
} %`%1W MO
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