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)); c;A ew!
} 0:nt#n~_
for(int i=0;i<nEndPos.length-1;i++) u!156X?[eU
{ &AkzSgP
nEndPos = nStartPos[i+1]; Wl}G[>P
} `pn-fk
nEndPos[nEndPos.length-1] = nFileLength; ixUiXP
} `K ~>!d_
} mAtG&my)
}1E_G
]Y/pSwnV
//启动子线程 crF9,p
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; Lt ZWs0l0
for(int i=0;i<nStartPos.length;i++) 7i%P&oB
{ m''iE
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), )Q N=>J
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), DXw9@b
nStartPos,nEndPos,i); }sm56}_
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 3n=cw2FG
fileSplitterFetch.start(); et7T)(k0
} 4%Wn}@
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), h_}BmJh_
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); ?7uStqa
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", YV>VA<c
nEndPos = " + nFileLength); ce-m)o/
// fileSplitterFetch[nPos.length-1].start(); !3gpiQH{
|Cxip&e>
+=lcN~U2
//等待子线程结束 Y=#mx3.
//int count = 0; L>K39z~,
//是否结束while循环 n$Oky-P"
boolean breakWhile = false; d%"@#bB
{yl/T:Bh&
`~s,W.Eu4
while(!bStop) =Am*$wGI
{ D6@4
write_nPos(); 7{6cLYl
Utility.sleep(500); g#bfY=C
breakWhile = true; 5<>R dLo
b&_u O
Hr64M0V3B
for(int i=0;i<nStartPos.length;i++) HhT8YH
{ ](( >i%%~
if(!fileSplitterFetch.bDownOver) &bRxy`ZH
{ % /wP2O<
breakWhile = false; 0zkT8'v
break; c&iK+qvh{
} 4FP~+
} |'>E};D
if(breakWhile) R2Fh^x
break; clU3#8P!=
9jJ/ RXp
JCMEhI6d*
//count++; Z~.]ZWj-
//if(count>4) w1/T>o
// siteStop(); MsVI <+JZ
} ?5+KHG*)
GF,|;)ly
z jNjmC!W
System.err.println("文件下载结束！"); F<'l'AsC-
} c$UpR"+
catch(Exception e){e.printStackTrace ();} ]9l%
} `0i}}Zo
@=| b$E
;),O*Z|"v
//获得文件长度 M%dl?9pbq
public long getFileSize() 3[g++B."pC
{ 3Tte8]0
int nFileLength = -1; #p:jKAc3
try{ 1Z{p[\k
URL url = new URL(siteInfoBean.getSSiteURL()); )@&?i.
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); d?+oT0pCH
httpConnection.setRequestProperty("User-Agent","NetFox"); bT6)(lm
)*AA9
x;b+gIz*
int responseCode=httpConnection.getResponseCode(); m"> =QP
if(responseCode>=400) 7XI4=O};&%
{ 5@r Zm4U
processErrorCode(responseCode); fbbl92p
return -2; //-2 represent access is error EG:WE^4
} hF%~iqd
Bv|9{:1%X}
!-}*jm p<
String sHeader; UK9MWC5g9
o[+|n[aT)3
9;WOqBD
for(int i=1;;i++) b5,}w:
{ &JQ@(w
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); %<o$ J~l~
//Utility.log(in.readLine()); 'f<_SKd
sHeader=httpConnection.getHeaderFieldKey(i); ,f""|X5
if(sHeader!=null) [LEh
{ kIZdND&
if(sHeader.equals("Content-Length")) HC`3AQ12!&
{ ,(Hmk(,
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); !`Yi{}1_
break; 9Q5P7}%p
} Nk~dfY<s
} wN0OAbtX'
else zNTu j p
break; B*?PB]
} >+LgJo R
} v\tbf
catch(IOException e){e.printStackTrace ();} 7 QJcRZ[lU
catch(Exception e){e.printStackTrace ();} :^L]Da3
SG o:FG
$Lbe5d?\
Utility.log(nFileLength); 8qLgB
_+Kt=;Y8
2g8P$+;
return nFileLength; `G5wiyH})
} ;Z~.54Pf{d
6&Ir0K/
Q]'!FmXf
//保存下载信息（文件指针位置） 3tcsj0Rb
private void write_nPos() ;GEu.PdxB
{ h*LL(ow5
try{ N~KRwsDH
output = new DataOutputStream(new FileOutputStream(tmpFile)); zjZTar1Re
output.writeInt(nStartPos.length); _o"3gfH&sJ
for(int i=0;i<nStartPos.length;i++) (dt_ D
{ >43yty\
// output.writeLong(nPos); ZvKMRW
output.writeLong(fileSplitterFetch.nStartPos); /'_ RI
output.writeLong(fileSplitterFetch.nEndPos); /6*.%M>r
} #\["y%;W
output.close(); UN4)>\Y
} y$Noo)Z
catch(IOException e){e.printStackTrace ();} %4KJ&R (>[
catch(Exception e){e.printStackTrace ();} *w,gi.Y3
} T1di$8
EKw\a
">&:(<
//读取保存的下载信息（文件指针位置） ?i=!UN
private void read_nPos() <vuX " 8
{ 25[/'7_"
try{ ?a9k5@s
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); `5&V}"lB
int nCount = input.readInt(); W)~.o/;
nStartPos = new long[nCount]; %$KO]
nEndPos = new long[nCount]; L=FvLii.
for(int i=0;i<nStartPos.length;i++) *g6o ;c
{ c9@jyq_H?
nStartPos = input.readLong(); vfDb9QP
nEndPos = input.readLong(); F}DD;K
} 4N0nU
input.close(); <5}du9@
} u@'zvkb@
catch(IOException e){e.printStackTrace ();} A+DYIS
catch(Exception e){e.printStackTrace ();} X&8,.=kt"
} yE9.]j
/~5YTe(F
Y"%o\DS*
private void processErrorCode(int nErrorCode) W A}@n
{ PCfs6.*5Mf
System.err.println("Error Code : " + nErrorCode); X($SBUS6
} zL}hFmh
1y;zPJ<ntm
04d$_1:}a
//停止文件下载 EC&,0i4n:
public void siteStop() 4TE ?mh}
{ 9r#{s Y
bStop = true; _?c.3+;s
for(int i=0;i<nStartPos.length;i++) r2'rfpQ
fileSplitterFetch.splitterStop(); n"Vd"}sU.
9X` QlJ2|
p00AcUTq
} IW_D$pq
} 4,DsB'
//负责部分文件的抓取 =1[g`b
**FileSplitterFetch.java &/?jMyD@
*/ !l^AKn|
package NetFox; ~mU_`o
kR(=VM JU
O3Mv"Py%
import java.io.*; lHqx}n@e
import java.net.*; mh]$g<*m
r/2:O92E
`0D1Nh"%k
public class FileSplitterFetch extends Thread { uJ\Nga<?
`%p6i| _Q
Zx 1z hc
String sURL; //File URL `aycYoD
long nStartPos; //File Snippet Start Position VC7F#a*V
long nEndPos; //File Snippet End Position ! fc)
int nThreadID; //Thread's ID dhkpkt<G8
boolean bDownOver = false; //Downing is over R*m"'|U
boolean bStop = false; //Stop identical IBh~(6
FileAccessI fileAccessI = null; //File Access interface R!G7;m'N1
Yk?q7xuT
D.`\ ^a
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException <DS6-y
{ >cL2PN_y
this.sURL = sURL; 7k|(5P;
this.nStartPos = nStart; @~3c;9LkY
this.nEndPos = nEnd; H/Q)zDP
nThreadID = id; i@L2W>{P
fileAccessI = new FileAccessI(sName,nStartPos);//定位 /)TEx}wk
} [+z:^a1?V
E ET 2|*}
Bdepvc}[#
public void run() ZRfa!9vl
{ ): C4}&l
while(nStartPos < nEndPos && !bStop) 3)SZVME1Z
{ {Z.@-Tl_
*xP:7K
J3;KQ}F.I
try{ n.RhA-O
URL url = new URL(sURL); 7d)' y
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); eUlb6{!y?
httpConnection.setRequestProperty("User-Agent","NetFox"); W<o0Z OO
String sProperty = "bytes="+nStartPos+"-"; W|U1AXU7/
httpConnection.setRequestProperty("RANGE",sProperty); edx'p`%d5
Utility.log(sProperty); U^\~{X
BH a>2N
/vu!5?S
InputStream input = httpConnection.getInputStream(); RiG!TTa b
//logResponseHead(httpConnection); p]=;t"
GGtrH~zx
pSFWNWQ'B
byte[] b = new byte[1024]; lJ#>Y5Qg
int nRead; \S@6@UGv
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) =)8fE*[s
{ d?Cl04
nStartPos += fileAccessI.write(b,0,nRead); /|AuI qW
//if(nThreadID == 1) e~?]F0/
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); J7o?h9
} wP?q5r5
|0p'p$%
#jiqRhm
Utility.log("Thread " + nThreadID + " is over!"); yTiqG5r
bDownOver = true; 89mre;v`
//nPos = fileAccessI.write (b,0,nRead); )n@3@NV
} q(^J7M)
catch(Exception e){e.printStackTrace ();} 2"mj=}y6
} Ms)zEy>[Ql
} TVwYFX
"s9gQAoaO
ZQA C&:
//打印回应的头信息 5&=n
public void logResponseHead(HttpURLConnection con) m28w4
{ ?Nql7F4
for(int i=1;;i++) FoCkTp+/
{ %$| k3[4V
String header=con.getHeaderFieldKey(i); " SqKS,J
if(header!=null) Y3>\;W*?
//responseHeaders.put(header,httpConnection.getHeaderField(header)); #HYkzjb
Utility.log(header+" : "+con.getHeaderField(header)); ?GU!ke p
else 3HR]TQ%r
break; QPE.b-S
} `wd*&vl
} W[<":NX2
Ct+%
;tiUOixJ
public void splitterStop() ZH_4'm!^g|
{ :exuTn
bStop = true; ',Pk>f]AB-
} mXj Ljgc}
5N<v'6&=
Z"Ni Y
} i]%"s_l
+Q0-jS#d
S'p`ECfVMA
/* KBA%
**FileAccess.java @A'1D@f#
*//文件访问(定位，写) e/jM+%
package NetFox; v=-3 ,C
import java.io.*; z}8L}:
@ibPL+~-_
UyKG$6F?3
public class FileAccessI implements Serializable{ j)6B^!
n3j h\
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 *r$.1nke
RandomAccessFile oSavedFile; +Z2<spqG
long nPos; KXCmCn
>I~z7JS
^QR'yt3e
public FileAccessI() throws IOException ;o459L>sW
{ w1(06A}/
this("",0); v};qMceJ
} X$Vz
Go7hDmu
5?0gC&WfN
public FileAccessI(String sName,long nPos) throws IOException ]GKx[F{)
{ )'`AX\
oSavedFile = new RandomAccessFile(sName,"rw"); f<p4Pkv
this.nPos = nPos; <>Ddxmw
oSavedFile.seek(nPos); `h5eej&s(
} L#q9_-(#
x`vs-Y:P
:";D.{||
public synchronized int write(byte[] b,int nStart,int nLen) !H=k7s
{ ]Ja8i%LjOG
int n = -1; e4%*I8 ^e
try{ H<7DcwXv
oSavedFile.write(b,nStart,nLen); Ilu`b|%D
n = nLen; ruA+1-<f
} 13_~)V
catch(IOException e) ;Jn0e:x`E
{ -7z y
e.printStackTrace (); *oX]=u&
} pQ(eF0KG
Ss! 3{VW
5=h'!|iY
return n; 1$D`Z/N"A
} ;s.5\YZ"k
Q1\k`J
$"{3yLg
} ;VlZd*M?
2*wO5v
>fA@tUQB
/* \"`>-v"h
**SiteInfoBean.java UAXF64w{
*/ `pd
package NetFox; Bd~cY/M
4S0++Hp4
^@*zH?Rx{
public class SiteInfoBean { RR"WO
[aZ v?Z
&Yf#O*
private String sSiteURL; //Site's URL bZay/ Zkj
private String sFilePath; //Saved File's Path Hu(flc+z"
private String sFileName; //Saved File's Name A~GtK\=;
private int nSplitter; //Count of Splited Downloading File K M\+
2*q: ^
3 [)s;e
public SiteInfoBean() _Z66[T+M
{//nSplitter的缺省值为5 KD"&_PX
//default value of nSplitter is 5 OWXye4`*
this("","","",5); /.kna4k
} QJIItx4hE
y(3c{y@~X
Ma=6kX]
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) }vUlTH
{ q?-3^z%u
sSiteURL= sURL; ncJFB,4
sFilePath = sPath; feI[M;7u
sFileName = sName; Z~phOv
this.nSplitter = nSpiltter; FO(0D?PCR
7?!Z+r
-Xxu/U})%
} <\d|=>;
$,e?X}4
)y/DGSd
public String getSSiteURL() PVD ~W)0m*
{ ?%xhe
return sSiteURL; teOBsFy/I
} "H="Ip!s
x !:9c<
!` M;#
public void setSSiteURL(String value) 3q|cZQK!1
{ >4|c7z4
sSiteURL = value; lKV\1(`
} @"{'j
gF,[u
!&a;P,_Fb
public String getSFilePath() Z]aK'
{ MB8SB
return sFilePath; #NN"(I
} G V:$;
EAD0<I<>
u3*NO )O
public void setSFilePath(String value) iIGI=EwZ
{ A`x -L
sFilePath = value; iJZ|[jEDV
} JIP+ !2
lLkmcHu
,jbGM&.C
public String getSFileName() %0NkIQ`C
{ zY1s7/$i
return sFileName; =CKuiO.j
} 5i4V5N>3
77xq/c[)
i[2bmd!H
public void setSFileName(String value) s^g.42?u
{ .L^pMU+!^
sFileName = value; gv#c~cX]
} . Z*j!{@c
# cN_y
_)zmIB(}m
public int getNSplitter() ws>WA{]gq
{ BSfm?ku"!
return nSplitter; tM^;?HL]
} *gd?>P7\0
<Qcex3
C(V[wvL
public void setNSplitter(int nCount) ~[|V3h4v
{ L$29L:
nSplitter = nCount; $(@o$%d
} "?.'{,Q
} @e!Zc3
/ojO>Y[<
Sa;<B:|
/* t;.^K\S4
**Utility.java @K$VV^wp
*/ %@lV-(5q
package NetFox; Lj&1K~U
n5Nan
:!JpP R5
public class Utility { ]6t]m2~\
k_D4'(V:b
4<G?
public Utility() 7Wwp )D
{ ~A`&/U
HzRX$IKB3(
O{k89{
} [=F>#8=
W.,% 0cZ
//线程睡眠 R^J.?>0
public static void sleep(int nSecond) t&GA6ML#s
{ 9VoDhsKk
try{ YgE]d?_h
Thread.sleep(nSecond); 4M @oj
} ]d@^i)2LF
catch(Exception e) 4F05(R8k
{ Zm%VG(l
e.printStackTrace (); kmm
} E rop9T1
} @br@[RpB
FI]P<)*r
//日志 DtzA$|Q}
public static void log(String sMsg) {$EH@$./
{ hLb;5u&!kW
System.err.println(sMsg); (jU/Wj!q
} \Fj5v$J-
-VS9`7k
p91`<>Iw
public static void log(int sMsg) |@ikx{W
{ Vbg10pV0
System.err.println(sMsg); q} ]'Q -
} j/)"QiS*?
} r<;l{7lY_
k?3S
;i<$7MR.e
/* ic%?uWN
**TestMethod.java .6> hD1'
*/ i 8l./Yt/
package NetFox; XB0a dp
&|v{#,ymeb
PX;Vo~6
public class TestMethod { 3/X-Cr+d
`J72+RA
M]}l^m>L
public TestMethod() drW~)6Lr@
{ ///xx/weblogic60b2_win.exe MaZM%W8Z
try{ exfmq
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); i 3m3zXt
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); gRBSt M&hU
SiteFileFetch fileFetch = new SiteFileFetch(bean); gks ==|s.
fileFetch.start(); bf& }8I$
} _p\629`
catch(Exception e){e.printStackTrace ();} kmryu=
=EQJqj1T
i.3cj1
} #@9)h
!X^Hi=aV
:6XguU
public static void main(String[] args) /\na;GI$
{ M70c{s`w5
new TestMethod(); 94\t1fE
} 2ck4C/ h
} ujU=JlJ7dl
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