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)); 8DsXw@o
} >uN)O-
for(int i=0;i<nEndPos.length-1;i++) RiX~YLeM
{ vhQIkB8
nEndPos = nStartPos[i+1]; <p74U( V
} P:gN"f6
nEndPos[nEndPos.length-1] = nFileLength; 8~>5k
} - s,M+Q(<
} ~:\QC
udV.$N
{:;599l
//启动子线程 Mr3;B+S
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; Qwm#6{5
for(int i=0;i<nStartPos.length;i++) C\B&'+uR
{ lnk`D(>W
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), v0yaFP#kG
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), ?zD?-
nStartPos,nEndPos,i); Z`=[hu
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); !5;A.f
fileSplitterFetch.start(); !6UtwCVR
} xA-u%Vf7@
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), ;QA`2$Ow
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); +v`?j+6z
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", `T gwa
nEndPos = " + nFileLength); < c}cgD4
// fileSplitterFetch[nPos.length-1].start(); >+ZG{'!j
El}."}l&
RiY9[ec2
//等待子线程结束 +x3T^G
//int count = 0; cnUYhxE+s
//是否结束while循环 &{Zt(%\ '
boolean breakWhile = false; i+2fWi6Z+
j}2,|9ne
S|{'.XG
while(!bStop) Tw!]N%E
{ y3]7^+k
write_nPos(); r pv`%
Utility.sleep(500); G8y:f%I!b
breakWhile = true; lm?1 K:+[
i,{'}B
hpxqL%r
for(int i=0;i<nStartPos.length;i++) :jol Nl|a
{ ]ZQ3|ZJ?<
if(!fileSplitterFetch.bDownOver) ]pZxbs&Vb
{ '8Q:}{
breakWhile = false; ~i4h.ZLj
break; %V>Ss9;/8
} WW'8&:x
} Hqel1J
if(breakWhile) `kn 'RZR
break; .#M'
'.sS"QdN
Hl,.6>F?
//count++; `h>a2
//if(count>4) %6\e_y%
// siteStop(); 6^vMJ82U
} Ag3[Nu1
\"]vSx>
5AvbKT
System.err.println("文件下载结束！"); q K sI}X~
} ewNzRH,b
catch(Exception e){e.printStackTrace ();} 03F%!Rm/j
} 1}moT#
R6^U9fDG
N3D{t\hg
//获得文件长度 (vq0Gl
public long getFileSize() )T-C/ 3
{ PdUlwT?8C
int nFileLength = -1; #1INOR9
try{ jE /pba4R
URL url = new URL(siteInfoBean.getSSiteURL()); 5'JONw'\
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); Z/#&c
httpConnection.setRequestProperty("User-Agent","NetFox"); ~i)m(65:
1:7 uS.
$\S;f"IM.
int responseCode=httpConnection.getResponseCode(); [Yo3=(7J
if(responseCode>=400) tE i-0J
{ :ET05MFs\#
processErrorCode(responseCode); K%Dksx7ow
return -2; //-2 represent access is error F/MzrK\':m
} s*"Yi~
ra="4T$va
gnW]5#c@
String sHeader; ^hG Y,\K9
NQ7j{dJ?
*Y4h26
for(int i=1;;i++) -Wp69DP6q
{ aq'dC=y
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); PNm WZW*
//Utility.log(in.readLine()); f L @rv
sHeader=httpConnection.getHeaderFieldKey(i); O}4(v#
if(sHeader!=null) \E9Hk{V:6
{ XS$5TNI
if(sHeader.equals("Content-Length")) !ke_?+8sY
{ ]:lqbg[J
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); yZ {H
break; (&n4^tJ+_
} 5|&:l8=
} ?\_N*NEtK
else Ix+===6
break; +-b:XeHSZ
} %Pr PCT
} bjgf8427I
catch(IOException e){e.printStackTrace ();} Hwr# NKz-
catch(Exception e){e.printStackTrace ();} @]*b$6tt
%+PWcCmn
PQla-
Utility.log(nFileLength); .'3&!#3
:}r^sD
B;SN}I
return nFileLength; ;aZ$qgN*Y
} R<}WNZl
h@{U>U7
aq~g54
//保存下载信息（文件指针位置） *gu4%
private void write_nPos() E,6(/`0H*
{ Ka[@-XH
try{ :HSqa9>wa
output = new DataOutputStream(new FileOutputStream(tmpFile)); v 4@=>L
output.writeInt(nStartPos.length); 13oR-Stj|
for(int i=0;i<nStartPos.length;i++) T6s~f$G
{ /O"IA4O
// output.writeLong(nPos); EJ$-
output.writeLong(fileSplitterFetch.nStartPos); X[L6Av
output.writeLong(fileSplitterFetch.nEndPos); !olvP*c"
} +\SNaq~&
output.close(); O34'c_ fZ
} &!I^m
catch(IOException e){e.printStackTrace ();} E?c)WA2iH
catch(Exception e){e.printStackTrace ();} }}a<!L,{
} sb 3l4(8g
?Ji.bnfK
3kxI'0&T
//读取保存的下载信息（文件指针位置） pfj%AP:
private void read_nPos() <VP@#
{ zk+&5d4(
try{ M8Y\1#~
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); 2ql7*g?Uq@
int nCount = input.readInt(); iz'#K?PF_
nStartPos = new long[nCount]; NTRw:'
nEndPos = new long[nCount]; %|(~k*s4
for(int i=0;i<nStartPos.length;i++) {I s?>m4
{ RX",Zt$q
nStartPos = input.readLong(); po~l8p>
nEndPos = input.readLong(); /yHM=&Vg]
} Fs q=u-= :
input.close(); wH&Rjn
} zh5{t0E}C
catch(IOException e){e.printStackTrace ();} "65@8xt==
catch(Exception e){e.printStackTrace ();} 5.J$0wK'6
} du2q6"
S[fzy$">
hw`+,_ g
private void processErrorCode(int nErrorCode) ZoJ:4uo N`
{ MRvtuE|g
System.err.println("Error Code : " + nErrorCode); C3fSSa%b
} ]JQk,<l5E
AL/`Pqlk
k[oU}~*U+
//停止文件下载 YH`/;H=$G/
public void siteStop() Ba/Z<1)
{ zGFo-C
bStop = true; O`e0r%SJ
for(int i=0;i<nStartPos.length;i++) ^n5[pF}Gw
fileSplitterFetch.splitterStop(); Ij>x3L\-
dbGW`_zQ4
fRo_rj _
} z^ +CD-
} X<s']C9c
//负责部分文件的抓取 -d\O{{%>.z
**FileSplitterFetch.java =Haqr*PDx
*/ gO-C[j/
package NetFox; Yo:l@(
nGA'\+zjL
~o`I[-g)
import java.io.*; Xui${UYN
import java.net.*; b?h9G3J_a
*&)<'6
,)A^3Q*
public class FileSplitterFetch extends Thread { 5J1A|qII
0N.tPF}
pYV$sDlD
String sURL; //File URL j(G}4dib
long nStartPos; //File Snippet Start Position oo7&.HWf
long nEndPos; //File Snippet End Position N$J)Ow
int nThreadID; //Thread's ID XtfO;`
boolean bDownOver = false; //Downing is over O4FW/)gq
boolean bStop = false; //Stop identical >jAr9Blz]
FileAccessI fileAccessI = null; //File Access interface \sFdp!M}2
yG58?5\9
SV.\B
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException pRmnS;*z&
{ Ltpd:c
this.sURL = sURL; ~*-ar6
this.nStartPos = nStart; H n+1I
this.nEndPos = nEnd; ")7,ZN;
nThreadID = id; %>'2E!%
fileAccessI = new FileAccessI(sName,nStartPos);//定位 cH6ie?KvAo
} d -6[\S#
DHGv< F@
w\=zTHo88
public void run() 9Qp39(l:
{ 9"2.2li5$
while(nStartPos < nEndPos && !bStop) 94%gg0azp
{ }[Uh4k8P
ME~ga,|K
bJe*J\){
try{ 49}yw3-
URL url = new URL(sURL); [8.ufpZ
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 8 f%@:}H
httpConnection.setRequestProperty("User-Agent","NetFox"); 0CI?[R\
String sProperty = "bytes="+nStartPos+"-"; >]Hz-2b
httpConnection.setRequestProperty("RANGE",sProperty); }5bh,'
Utility.log(sProperty); 4NbX!"0
4cL NPl<
d9|dHJf
InputStream input = httpConnection.getInputStream(); l.1)%q&@^
//logResponseHead(httpConnection); W5(t+$L.
Jl&bWp^3
%([$v6y
byte[] b = new byte[1024]; 2F^ %d9`
int nRead; NKLGbH
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) Y32F{ z
{ 2.}<VivT
nStartPos += fileAccessI.write(b,0,nRead); ^G=wRtS
//if(nThreadID == 1) VgZ<T,SuW
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); m\7-/e2a
} }p}i_'%
_`/0/69
hSaS2RLF
Utility.log("Thread " + nThreadID + " is over!"); fOJk+? c
bDownOver = true; \8Mkb]QA
//nPos = fileAccessI.write (b,0,nRead); mc|T}B
} <qZXpQ#
catch(Exception e){e.printStackTrace ();} COFs?L.`
} l7aGo1TcIh
} (y^oGY;
9~zh]deH
8_>\A= E
//打印回应的头信息 O 4N_lr~
public void logResponseHead(HttpURLConnection con) I"Ji_4QV
{ BQSA;;n]
for(int i=1;;i++) qh0)~JL4
{ 5h1!E
String header=con.getHeaderFieldKey(i); o}v #Df
if(header!=null) dVVeH\o
//responseHeaders.put(header,httpConnection.getHeaderField(header)); _|DP
Utility.log(header+" : "+con.getHeaderField(header)); pW:h\}%`n
else #1hT#YN
break; /2>-h-zBjw
} .`Z{ptt>
} H; TmG<S
MP[v 9m@
Q+mMpI
public void splitterStop() #H O\I7m
{ wuzz Wq
bStop = true; X$/3
} -/x +M-X#
Vnh +2XiK
+Jt"JJ>%k
} qqw6p j
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W{ eu_
/* @kvp2P+O
**FileAccess.java ?[RG8,B
*//文件访问(定位，写) kUP[&/Lc
package NetFox; d/Py,
import java.io.*; C^nL{ZP,
~e{2Y%
X&wK<
public class FileAccessI implements Serializable{ 6sP;O,UX
W3<O+S&
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 ?b#?Vz
RandomAccessFile oSavedFile; }S#.Pw%
long nPos; `yQHPN0/
,<EmuEw |
#H!~:Xu
public FileAccessI() throws IOException X[@>1tl
{ EHzZ9zH\
this("",0); Q~xR'G[N
} cYbO)?mC_
Ku&(+e
*r-Bt1
public FileAccessI(String sName,long nPos) throws IOException rA1 gH6D
{ @J r
oSavedFile = new RandomAccessFile(sName,"rw"); 6,@M0CX
this.nPos = nPos; b%oma{I=.c
oSavedFile.seek(nPos); ;euWpE;E\#
} PU'v o4
aLsGden|
(XW#,=rYk
public synchronized int write(byte[] b,int nStart,int nLen) Y\op9Fw
{ U!e4_JBR'
int n = -1; l w%fY{
try{ 2f:'~ P56
oSavedFile.write(b,nStart,nLen); wR;l"*j
n = nLen; \6lXsu;I.X
} 9723f1&Vd
catch(IOException e) Fe=4^.
{ {^\-%3$
e.printStackTrace (); RF;N]A?*
} VtKN{sSnu
mD=?C
K[ \z'9Q
return n; !3b%Q</M H
} kEXcEF_9P
5G!X4%a
~Fx[YPO,
} o?b%L
Gg!))I+
w1}[lq@
/* c8'8DM
**SiteInfoBean.java S:}s|![p
*/ D3K`b4YV
package NetFox; 2Z97Tq
*/\.-L{h
QB.7n&u
public class SiteInfoBean { 1]<!Xuk^f
UP`q6]P
]SPB c
private String sSiteURL; //Site's URL 5{5ABV
private String sFilePath; //Saved File's Path FjydEV
private String sFileName; //Saved File's Name jG2w(h/"
private int nSplitter; //Count of Splited Downloading File wiGwN
.( J/*H
MCCZh{uo
public SiteInfoBean() |HEw~x<=
{//nSplitter的缺省值为5 Z\L@5.*ydE
//default value of nSplitter is 5 |")x1'M
this("","","",5); U<t-LF3
} $"i690
w* I+~o-
f8 jaMn9o
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) wY95|QS
{ kmoJ`W} N
sSiteURL= sURL; +doT^&2u*
sFilePath = sPath; {eXYl[7n
sFileName = sName; aYgJTep>r
this.nSplitter = nSpiltter; e?YbG.(E9
A1q^E(}O
p4t)Z#0
} [1*/lt|+p
/kz&9FM
*I67SBt
public String getSSiteURL() E8i:ER $$7
{ [FL I+;gY
return sSiteURL; mig3.is
} (HI%C@e9
]Yg EnZ
K5>:WiY
public void setSSiteURL(String value) Q.1ohj0)
{ =dBrmMh
sSiteURL = value; nrIL_
} #+ '@/5{n
+][P*/Ek
5B 7*Z
public String getSFilePath() G C'%s
{ e_], O_Z
return sFilePath; md"%S-a_dT
} kDq%Y[6Z
W~3tQ!
7Ca\ (82
public void setSFilePath(String value) YZRB4T9
{ >e;STU
sFilePath = value; 3+3m`%G
} l7,qWSsnK
Fz&ilB
&|}IBu:T
public String getSFileName() J~3T8e#
{ ,,@`l\Pgd
return sFileName; A.9'pi'[9Q
} k!=GNRRZE
~[TKVjyO
Pki4wDCTW
public void setSFileName(String value) WG !t!1p
{ q_y,j&
sFileName = value; Tki/d\!+
} WWW#s gM%
^r*%BUU9]%
|.O!zRm
public int getNSplitter() 1L8ULxi_?]
{ %K'*P56
return nSplitter; FJ~_0E#L
} 6BU0hV
ASZ5;N4u
ynZ[c8.
public void setNSplitter(int nCount) \h7J/es^p!
{ uuYH6bw*d
nSplitter = nCount; D4Y!,7WEVt
} ClMtl59
} 4Sstg57x~
Of7) A
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/* r@[VY g~
**Utility.java }SMJD
*/ {IPn\Bka
package NetFox; j(6$7+2qN
5m.KtnT)
f:[d]J|
public class Utility { Uk*;C
FW)^O%2s
?[S >&Vq
public Utility() frmqBCVJ:
{ lii]4k+z
L);||]B
ra%R:xX
} 85|95P.<
0?F@iB~1F
//线程睡眠 @ojg`!,
public static void sleep(int nSecond) E]H
{ LPapD@Z
try{ zh^jWu
Thread.sleep(nSecond); lv00sa2z
} %<wQ
catch(Exception e) HTUYvU*-
{ +f\pk \Ith
e.printStackTrace (); sm2p$3v
} hnsa)@
} Fp5NRM*-!
s3Krob`C5
//日志 TOco({/_/
public static void log(String sMsg) EtR@sJ<
{ m0I #
System.err.println(sMsg); 3{Ek-{9
} f/0v' Jt
2H?I'<NoC
9{O2B5u1
public static void log(int sMsg) Et}C`vZ+Ve
{ :7$\X[
System.err.println(sMsg); /$FXg;h9$
} 28T\@zi
} u=@h`5-fp
7>PF~=
RwAbIXG{0
/* y:g7'+c
**TestMethod.java NJ|NJp&0
*/ 3x"@**(Q
package NetFox; =2RhPD
9N~8s6Ob
tC2 )j7@
public class TestMethod { ]z-']R;
z:Xj_ `p
Bs+c2R
public TestMethod() u<l#xud
{ ///xx/weblogic60b2_win.exe hmK8jl<6
try{ CRZi;7`*1
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); xa87xX=a
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); CS~=Z>6EjA
SiteFileFetch fileFetch = new SiteFileFetch(bean); X'V+^u@W
fileFetch.start(); 8A2if9E3
} `pP9z;/Xq
catch(Exception e){e.printStackTrace ();} Dk)@>l:gI,
$.oOG"u0]
'R^iKNPs
} p>k]C:h
6RK ~Dl&g
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public static void main(String[] args) g~~m'^
{ kx|me~I
new TestMethod(); q{a#HnZo"
} sW;7m[o
} _ymJ~MK
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