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)); NEX\+dtE~0
} k?_Miqr
for(int i=0;i<nEndPos.length-1;i++) hE>Mo$Q(
{ ;&iQNXL
nEndPos = nStartPos[i+1]; o/Z?/alt4
} 3N;X|pa
nEndPos[nEndPos.length-1] = nFileLength; }%%| '8
} pBHr{/\5
} u|+O%s TQ
Z yIn>]{
lO:[^l?F
//启动子线程 (`T:b1
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; 8tsW^y;S
for(int i=0;i<nStartPos.length;i++) I(C_}I>Wb
{ LNe-]3wB
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), !dZC-U~
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), N/Z<v* i"
nStartPos,nEndPos,i); g4Tc (k#
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); +YP,LDJ!v
fileSplitterFetch.start(); NO'-HKHj
} )jnxR${M
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), ,<%],-Lt[
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); 7dAa~!/(
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", &QvWT+]c'0
nEndPos = " + nFileLength); ^!=+$@<
// fileSplitterFetch[nPos.length-1].start(); @@+\
y6$5meh.T
qPWYY
//等待子线程结束 #\fApRL
//int count = 0; [N{Rd[{QTL
//是否结束while循环 z55P~p
boolean breakWhile = false; ?L'ijzP
2nk}'HBe
0nBAO
while(!bStop) zg[ksny
{ euQd
write_nPos(); J3C"W794}
Utility.sleep(500); 3rs=EMz:w
breakWhile = true; >*EcX3
-v`;^X
L~~;i'J
for(int i=0;i<nStartPos.length;i++) qL(Qmgd
{ 8hdd1lVKO8
if(!fileSplitterFetch.bDownOver) Wa , #
{ 9[/Gd{`XC
breakWhile = false; `*N2x\+X
break; lr=*Ty(V
} ZfS-W&6Z
} iGM-#{5
if(breakWhile) 6:@tHUm
break; uS3J^=>@(a
@va6,^)
7|*|xLrVY
//count++; (C1]R41'
//if(count>4) D[ny%9 :
// siteStop(); 5ZUqCl(PX)
} F?3a22Zg#
#TRPq>XzD
7h,SX]4Q
System.err.println("文件下载结束！"); %*zgN[/w
} m;k' j@:
catch(Exception e){e.printStackTrace ();} UfXqcyY(
} [/6IEt3}B
nx84l7<
g?)9zJ9
//获得文件长度 S'lZ'H/
public long getFileSize() A6= Um%T
{ q8`JRmt)H
int nFileLength = -1; ! p458~|
try{ qa2QS._m
URL url = new URL(siteInfoBean.getSSiteURL()); NJwcb=*
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); #X`j#"Ov2(
httpConnection.setRequestProperty("User-Agent","NetFox"); % ?@PlQ
%\2 ll=p1
Z#%4QIz?
int responseCode=httpConnection.getResponseCode(); NbSkauF~b
if(responseCode>=400) X^7bOFWE
{ =T!iM2
processErrorCode(responseCode); y.HE3tH
return -2; //-2 represent access is error ZF>zzi+@
} b1R%JY7/S
6l<q
X*/jna"*
String sHeader; ZU5hHah.t
gM '_1zs U
[YLaRr
for(int i=1;;i++) ['Hl$2 j
{ 0PjWfM8%
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); \GEFhM4)
//Utility.log(in.readLine()); "o+< \B~
sHeader=httpConnection.getHeaderFieldKey(i); I5 "Z
if(sHeader!=null) 9m/v^
{ p$0G EYwM
if(sHeader.equals("Content-Length")) (0bvd
{ amK"Z<V F
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); TkM8GK-3
break; TW" TgOfd
} n>"0y^v
} 5(]=?$$*t
else mR)Xq=
break; _Y?p =;
} nn5tOV}QE
} eF823cH2x_
catch(IOException e){e.printStackTrace ();} *0^!%Y'/4
catch(Exception e){e.printStackTrace ();} >,yE;zuw
tt$DWmm
9@9(zUS|
Utility.log(nFileLength); ,6uON@
|#^wYZO1U
T@ (MSgp9
return nFileLength; @FKm_q
} Z%E;*R2+:>
4V@raI-
$WED]X@X!
//保存下载信息（文件指针位置） i 3?=up!
private void write_nPos() N =FX3Z
{ dDK4I3a
try{ #N.W8mq
output = new DataOutputStream(new FileOutputStream(tmpFile)); |4^us|XY
output.writeInt(nStartPos.length); US[{ Q
for(int i=0;i<nStartPos.length;i++) 2~h! ouleY
{ fkbHfBp[(A
// output.writeLong(nPos); 1tw>C\
output.writeLong(fileSplitterFetch.nStartPos); roSdcQTeT
output.writeLong(fileSplitterFetch.nEndPos); 3#<b!Yz
} |`B*\\1
output.close(); ^lud2x$O^C
} 4jbqV
catch(IOException e){e.printStackTrace ();} <=[,_P6|
catch(Exception e){e.printStackTrace ();} FrT.<3
} {]BPSj{B
ek\8u`GC
+L03.rf
//读取保存的下载信息（文件指针位置） 6[b'60CuZL
private void read_nPos() jeXP|;#Una
{ -}#=L@
try{ Jh`Pq,B:
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); dCc"Qr[k
int nCount = input.readInt(); ?-C=_eZJ
nStartPos = new long[nCount]; g?&_5)&
nEndPos = new long[nCount]; =;Ap+}
for(int i=0;i<nStartPos.length;i++) s&&8~ )H
{ z=%&?V
nStartPos = input.readLong(); :59fb"^$
nEndPos = input.readLong(); ;\-f7!s
} Hj(ay48
input.close(); Lu?MRF f
} }x!=F<Q!r
catch(IOException e){e.printStackTrace ();} ]z3!hgTj
catch(Exception e){e.printStackTrace ();} Ck.LsL-
} rHYSS0*3
G8AT] =
}.*"ezaZw
private void processErrorCode(int nErrorCode) Jy<hTd*q
{ +U9m
System.err.println("Error Code : " + nErrorCode); b* (~8JxZ
} n@%Q 2_
{&7%wZ"t_
M:TN^ rA|
//停止文件下载 3kqO5+,C
public void siteStop() KTLq~Ru
{ Rn?Yz^ 1q
bStop = true; 3lr9nBR
for(int i=0;i<nStartPos.length;i++) \"k[y+O],4
fileSplitterFetch.splitterStop(); I "Qf};n
|p_\pa1&
@>:V?
} ["O/%6b9+
} (B+CI%= D
//负责部分文件的抓取 Q+bZZMK5,U
**FileSplitterFetch.java :DWvH,{+&
*/ |z.x M>
package NetFox; E3hql3=
p}}pq~EH/
&k53*Wo
import java.io.*; [Ey[A|g
import java.net.*; a9LK}xc={
=f~8"j
_EHz>DJ9
public class FileSplitterFetch extends Thread { omdoH?
M9~eDw'Pr
+;#z"m]
String sURL; //File URL B|I9Ex~L
long nStartPos; //File Snippet Start Position =bKz$ _W
long nEndPos; //File Snippet End Position XS#Jy n
int nThreadID; //Thread's ID &<dC3o!
boolean bDownOver = false; //Downing is over g}@W9'!
boolean bStop = false; //Stop identical ^lvYj E
FileAccessI fileAccessI = null; //File Access interface 9f=L'{
srL|Y&8p
<[l0zE5Z8'
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException !m {d6C[
{ <b.O^_zQF
this.sURL = sURL; yj$a0Rgkv
this.nStartPos = nStart; 2eC`^
this.nEndPos = nEnd; t@(:S6d
nThreadID = id; t_xO-fT)
fileAccessI = new FileAccessI(sName,nStartPos);//定位 S"=y>.#
} U~CG(9
WNnB s
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public void run() vQH6CB"
{ )t#>fnN
while(nStartPos < nEndPos && !bStop) ]`+J!G,
{ "5wer5? t
Ty&Ok*
,vcg%~-
try{ y,/Arl}yc
URL url = new URL(sURL); W^e"()d/Z
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); JX)%iJq#
httpConnection.setRequestProperty("User-Agent","NetFox"); wjzR 8g0bQ
String sProperty = "bytes="+nStartPos+"-"; Qr.SPNUFK
httpConnection.setRequestProperty("RANGE",sProperty); Uf,fd
Utility.log(sProperty); OK]_.v}
rbt/b0ET
?zpN09e
InputStream input = httpConnection.getInputStream(); 6lAHB*`
//logResponseHead(httpConnection); 8el\M/u{
uD=FTx
*`]#ntz9
byte[] b = new byte[1024]; D[H #W[
int nRead; eo [eN.
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) U0m 5Rc
{ c3__=$)'kP
nStartPos += fileAccessI.write(b,0,nRead); zk++#rB
//if(nThreadID == 1) Hd_W5R
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); zNo>V8B(
} 1CmjEAv%/
Ht,+KbB
b'O>qQ
Utility.log("Thread " + nThreadID + " is over!"); \cx==[&(
bDownOver = true; OF1fS\P<>
//nPos = fileAccessI.write (b,0,nRead); af-
} -dyN Ah?=
catch(Exception e){e.printStackTrace ();} x=I|O;"><
} 5 (cgHr"
} CT0 ~
a%YohfsY?U
lKSd]:3Xm
//打印回应的头信息 S_ER^Pkg
public void logResponseHead(HttpURLConnection con) 1@Gmzh
{ o"gtWAGH
for(int i=1;;i++) Dg=!d)\
{ u*6Y>_iA
String header=con.getHeaderFieldKey(i); umuE5MKY<
if(header!=null) $! R]!s
//responseHeaders.put(header,httpConnection.getHeaderField(header)); %AJTU3=0
Utility.log(header+" : "+con.getHeaderField(header)); !Y,*Zc$R
else &;2@*#,
break; I.>SC
} 5Tg[-tl
} ozOvpi:k3%
($T"m-e
elDt!9Pu
public void splitterStop() _&R lR
{ #qDMUN*i
bStop = true; TbQ5
} Y;"rJxHD
@b3jO
cii! WCu
} NpAZuISD!
X3zpU7`Av+
0`Hr(J`F
/* T$IwrTF@?
**FileAccess.java M"\j7(
*//文件访问(定位，写) f=--$o0U~
package NetFox; lL;SP&
import java.io.*; J/xbMMb
3/s" ;Kg,
Ad)::9K?J
public class FileAccessI implements Serializable{ 6k+4R<
WlHK
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 X:kr$
RandomAccessFile oSavedFile; > }fw7X
long nPos; Bm$(4
_^MkC}8
xcM*D3
public FileAccessI() throws IOException b^^ .$Gu
{ Q:^.Qs"IK
this("",0); TfnBPO
} I6vy:5d
U'p-Ko#
UAEu.AT
public FileAccessI(String sName,long nPos) throws IOException UlQS]f~
{ tDQuimYu7
oSavedFile = new RandomAccessFile(sName,"rw"); ]9PQKC2&
this.nPos = nPos; Me2qOc^Z-
oSavedFile.seek(nPos); VdOcKP.
} ; S~
oY<R[NYKu
'`sZo1x%f
public synchronized int write(byte[] b,int nStart,int nLen) [I6&|Lz>
{ nsN|[E8
int n = -1; &rfl(&\oUi
try{ ;hb_jW-0W
oSavedFile.write(b,nStart,nLen); 6DT^:LHS
n = nLen; <5E: ,<
} z)F<{]%
catch(IOException e) RAU"
{ A+41JMH
e.printStackTrace (); c-oIP~,
} py }`thx
d}^G790
AMre(lgh
return n; L0X/
} %4,v2K
TGH"OXV*@
)%wNVW 0C
} 2+=:pc^
$(fhO
.K`EflN
/* wCgi@\
**SiteInfoBean.java wfQ^3HL
*/ b Od<x >@
package NetFox; FH)_L1n
&w%--!T
5>\~jf
public class SiteInfoBean { )>;V72
952l1c!
4A)@,t9+
private String sSiteURL; //Site's URL h,zM*zA_
private String sFilePath; //Saved File's Path l4$Iv:
private String sFileName; //Saved File's Name /i)>|U 4
private int nSplitter; //Count of Splited Downloading File @0 #JY:"
CmxQb,Uls
ybU_x
public SiteInfoBean() c^1tXu|&
{//nSplitter的缺省值为5 $*+IsP!
//default value of nSplitter is 5 @hwe
this("","","",5); sR;u#".
} Xv<K>i>k
({0:1*lF@
*CCh\+S7m
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) VT [TE
{ H b?0?^#
sSiteURL= sURL; bbs'>D3
sFilePath = sPath; :Z&<5
sFileName = sName; ^v5<*uf%m
this.nSplitter = nSpiltter; CB^.N>'
xi[\2g+
)F_nK f"a
} -pW*6??+?
./35_Vy/O
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public String getSSiteURL() Q 6n!u;
{ 3IG<Ot9
return sSiteURL; fj97_Q=
} 1) Nj.#)
#QNa| f#=
y.$Ae1a=
public void setSSiteURL(String value) hQ (84u
{ t76B0L{
sSiteURL = value; ^X;p8uBo
} 6aKfcvf &
nc^DFP
fS$;~@p
public String getSFilePath() :i>If:>g
{ hgK 4;R
return sFilePath; =Q*x=}NH
} ckYT69U
0.[tEnLZ
qLV3Y?S!L
public void setSFilePath(String value) VWK%6Ye0
{ }<^QW't_Y
sFilePath = value; "0 $UnR
} _tRRIW"Vx"
nJ}@9v F/
yoH,4,!G
public String getSFileName() K\FLA_J
{ H128T8?r[
return sFileName; b|-S;cw
} m*.+9 6
_:]g:F[ #
3EHB~rL/C
public void setSFileName(String value) :(iBLO<x
{ "hk {"0E
sFileName = value; xp}M5|
} hp`ZmLq/[
YQcaWd(
&z#`Qa3NI
public int getNSplitter() U$46=F|
{ uUb`Fy9
return nSplitter; x\oSD1t,
} ;!A=YXB
Y5c[9\'\
Y/sZPG}4
public void setNSplitter(int nCount) 03c8VKp'p
{ ~owodc
nSplitter = nCount; ?,i}Qr [Q
} iK=QP+^VN
} qOy0QZ#0
[ ebk u_
\CX6~
/* adPd}rt;
**Utility.java L2=:Nac
*/ ( k,?)
package NetFox; zdm2`D;~p
|nfMoUI
KP&xk13)
public class Utility { _+.JTk
q~^!Ck+#*
[{`2FR:Cd
public Utility() j^%N:BQ&
{ \ef:H&r
^HxIy;EQ<z
I1Otu~%d
} %/ctt_p0x
B77`azwF
//线程睡眠 SsPZva
public static void sleep(int nSecond) 9F[_xe@
{ [X91nUz#
try{ wh)F&@6 R!
Thread.sleep(nSecond); 0*_E'0L8e
} Ra"hdxH
catch(Exception e) {A'*3(8
{ "8"aYD_
e.printStackTrace (); K?Sy?Kz
} dyk(/#*7W
} .)SR3?
f!#+cM
//日志 +w-J;GLSy
public static void log(String sMsg) }*C*!?pcd
{ 3I(;c ,S
System.err.println(sMsg); K:^0*5Y-k
} `2hg?(ul
oEX^U4/=
91]sO%3
public static void log(int sMsg) k<5g
{ >ZW|wpO
System.err.println(sMsg); Y2;2Exp^
} T];dFv-GT
} uuxVVgWp{
qXhdU/ =
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/* 6oKdw|(Q#
**TestMethod.java 'uE;8.,
*/ .T)wG;+
package NetFox; TkJ[N4'0
#f<v%
aHVzBcCPh
public class TestMethod { #y[U2s Se
YM};85K
PfZS"yk
public TestMethod() b\"w/'XX
{ ///xx/weblogic60b2_win.exe D$7#&2y
try{ 78Du
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); J/O{x
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); +<j7^AEG
SiteFileFetch fileFetch = new SiteFileFetch(bean); UoPY:(?;i
fileFetch.start(); s*s~yH6
} Q@7d:v
catch(Exception e){e.printStackTrace ();} z~ywFk}KGd
R|v'+bv
H]pI$t3~
} yIrJaS-
Zk`yd8C
'E+"N'M|
public static void main(String[] args) 6pSi-FH
{ N0.|Mb"?t
new TestMethod(); E5$]0#jB
} ?3p7MjvZ
} ;AE-=/<
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