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)); #8XL :I
} ABh&X+YD
for(int i=0;i<nEndPos.length-1;i++) !w39FfU{
{ p{D4"Qn+P9
nEndPos = nStartPos[i+1]; ;dR=tAf0$Q
} ?D`T7KSe~D
nEndPos[nEndPos.length-1] = nFileLength; ?6^|ZtB
} 7zemr>sIh
} W-efv
n.}E5%qK
Cbm\h/PXl
//启动子线程 `aC){&AP(
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; T;5r{{
for(int i=0;i<nStartPos.length;i++) #,d I$gY
{ c;2#,m^
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), YW/QC'_iC
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), he(A3{'
nStartPos,nEndPos,i); `=lc<T^
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); "N?+VkZEv
fileSplitterFetch.start(); u #w29Pm
} (kv?33
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), _)T5lEFl=
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); ml`8HXK0
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", #OO>rm$
nEndPos = " + nFileLength); <h-vjz
// fileSplitterFetch[nPos.length-1].start(); A/7{oB:a
G<|8?6bq#
@#g<IBG=*
//等待子线程结束 v59dh (:`Z
//int count = 0; @.Icz
//是否结束while循环 1KM`i
boolean breakWhile = false; 9h4({EE2t
aJ") <_+
~*A8+@\R
while(!bStop) 4)|8Eu[p7
{ phnV7D(E
write_nPos(); VHJM*&5
Utility.sleep(500); aFz5leD
breakWhile = true; 5,-U.B}
},+wJ1
,'xYlH3s
for(int i=0;i<nStartPos.length;i++) *37uy_EpV
{ %h?x!,q Y
if(!fileSplitterFetch.bDownOver) !$-\;<bZw
{ YG[;"QR
breakWhile = false; #9-P%%kQ
break; (0YZZ93
} SN7"7joP<
} SCvVt
if(breakWhile) N,8/Y
break; =U%Rvm
AV9m_hZt
|KSy`lY-j>
//count++; 1cS}J:0P
//if(count>4) 8>,jpAN}r
// siteStop(); (q+)'H%iK
} 7(5xL T$
5[0 O'%$
y{dTp
System.err.println("文件下载结束！"); .ZvM^GJb
} ![]``g2
catch(Exception e){e.printStackTrace ();} i;LXu%3\
} z9FfU
35E_W>n
:8CvRO*<
//获得文件长度 1$M@]7e+!+
public long getFileSize() wr[,
{ At7>V-f}
int nFileLength = -1; &l3iV88
try{ Oo"^%F~%
URL url = new URL(siteInfoBean.getSSiteURL()); Ag{iq(X
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); d&ex5CU5
httpConnection.setRequestProperty("User-Agent","NetFox"); J5^'HU3
&|f@$ff
8GvJ0Jq}U
int responseCode=httpConnection.getResponseCode(); rM'=_nmi
if(responseCode>=400) xx[9~z=d
{ ZI=%JU(
processErrorCode(responseCode); "@??Fw!
return -2; //-2 represent access is error *h}XWBC1q
} uV!^,,~
{r@Ty*W} L
gw,UQbnu
String sHeader; ma"3qGy
]IoUwgpI)
VeW>[08
for(int i=1;;i++) *:ZDd
{ ?VP8ycm
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); N5a*7EJv+
//Utility.log(in.readLine()); bbrXgQ`s+w
sHeader=httpConnection.getHeaderFieldKey(i); c-B cA
if(sHeader!=null) 9FB19
{ zuUW|r
if(sHeader.equals("Content-Length")) G1vNt7
{ D#3\y*-y?
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); rg^'S1x|
break; XUz3*rfs
} bD/~eIcWL
} 3AU;>D^5
else Kx>qz.wwI?
break; Pi]19boM.
} xai*CY@cQ
} _f$^%?^
catch(IOException e){e.printStackTrace ();} YB-h.1T-
catch(Exception e){e.printStackTrace ();} d3D] k,
z6*X%6,8
r"P|dlV-
Utility.log(nFileLength); FoN|i"*l
Tj:B!>>
R}O_[
return nFileLength; -[cTx[Z,
} HMSO=)@+
Qk:Y2mL
8fl`r~bqZ
//保存下载信息（文件指针位置） uScMn/%
private void write_nPos() R%?9z 8-
{ gt@m?w(
try{ -*1J f&
output = new DataOutputStream(new FileOutputStream(tmpFile)); <sBbT`
output.writeInt(nStartPos.length); ML|FQ
for(int i=0;i<nStartPos.length;i++) f&Gt|
{ RZXjgddL
// output.writeLong(nPos); \G*0"%!U
output.writeLong(fileSplitterFetch.nStartPos); =ALTUV3/q
output.writeLong(fileSplitterFetch.nEndPos); bbE!qk;hEP
} U~:-roQ(\
output.close(); Dfmjw
} hb}+A=A=+
catch(IOException e){e.printStackTrace ();} g:hjy@ w
catch(Exception e){e.printStackTrace ();} ;lE%M
} ?8'*,bK
F(>Np2oi6
.+$Q<L
//读取保存的下载信息（文件指针位置） LY%WD%pL
private void read_nPos() 45@^L's
{ YtmrRDQs
try{ GPN]9
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); Fld=5B^}
int nCount = input.readInt(); AE[b},-[
nStartPos = new long[nCount]; JRB9rSN^
nEndPos = new long[nCount]; l3)}qu
for(int i=0;i<nStartPos.length;i++) oKuI0-*mR
{ 4h|c<-`>t
nStartPos = input.readLong(); k>;`FFQU>
nEndPos = input.readLong(); HiZ*+T.B
} R!}H;[c
input.close(); 6^]+[q}3
} !|^|,"A)
catch(IOException e){e.printStackTrace ();} b3=rG(0f
catch(Exception e){e.printStackTrace ();} 8A##\j)
} eA2@Nkw~)
%)1y AdG 8
-|$@-fY;
private void processErrorCode(int nErrorCode) bCRV\myd`
{ ,E S0NA
System.err.println("Error Code : " + nErrorCode); C5o#i*|
} Cd#(X@n
Bs^aII$
*4\:8
//停止文件下载 ua3~iQj-
public void siteStop() @>,^":`#
{ ]cHgleHQ
bStop = true; >g1~CEMN#
for(int i=0;i<nStartPos.length;i++) q'T4w!V(V
fileSplitterFetch.splitterStop(); >mwlsL~X
marQNZ
hOjk3 k
} Q /U2^
} $V-~Bu-
//负责部分文件的抓取 gb[5&>(#
**FileSplitterFetch.java NcBIg:V\c
*/ 9ijfRqI=x
package NetFox; 3lrT3a3vV
11Q1AN
0CnOL!3.I
import java.io.*; @0Ic3C[rH6
import java.net.*; Ni9/}bb
n<LEler#M
?WGA?J %2
public class FileSplitterFetch extends Thread { -*1d!
f,U.7E
)|ju~qbf
String sURL; //File URL P)Jgs
long nStartPos; //File Snippet Start Position L+b6!2O,
long nEndPos; //File Snippet End Position X_q\Sg
int nThreadID; //Thread's ID ha]VWt%}
boolean bDownOver = false; //Downing is over V(H1q`ao9
boolean bStop = false; //Stop identical D+TD 95t
FileAccessI fileAccessI = null; //File Access interface }|h# \$w
Ua:}Vn&!
I fK,b*%
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException *7uH-u"5d
{ P78g/p T
this.sURL = sURL; @a! #G
this.nStartPos = nStart; Dj"F\j 1
this.nEndPos = nEnd; Wf+cDpK
nThreadID = id; $0W|26;
fileAccessI = new FileAccessI(sName,nStartPos);//定位 >FeX<L
} Cjn#00
h79}qU
yb<fpM
public void run() y8]B:_iU9
{ 5AFJC?
while(nStartPos < nEndPos && !bStop) is?{MJZ_
{ pC#E_*49
w'>pY
R$R*'l
try{ !z\h|wU+
URL url = new URL(sURL); \1k79c
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 8SMxw~9$
httpConnection.setRequestProperty("User-Agent","NetFox"); {5Q!Y&N.%
String sProperty = "bytes="+nStartPos+"-"; E^B'4
httpConnection.setRequestProperty("RANGE",sProperty); 8?xE6
Utility.log(sProperty); )W^F2-{
ju8>:y8
1KU! tL
InputStream input = httpConnection.getInputStream(); Cwv9 a^
//logResponseHead(httpConnection); #|uCgdi
)HEa<P^kJl
Ki;*u_4{
byte[] b = new byte[1024]; xK>*yV
int nRead; 3(>B Ke
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) )*u8/U
{ `}p0VmD{NE
nStartPos += fileAccessI.write(b,0,nRead); 7y.kQI?3
//if(nThreadID == 1) /T"+KU*
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); mVj9,q0
} * `JYC
z0d.J1VW
34f?6K1c
Utility.log("Thread " + nThreadID + " is over!"); sU=H&D99
bDownOver = true; D(~U6SR
//nPos = fileAccessI.write (b,0,nRead); D,k6$`
} ]=\].% >
catch(Exception e){e.printStackTrace ();} H%[eV8
} C"y(5U)d
} dn&s*
#NQMy:JHD)
.j ?W>F
//打印回应的头信息 ,V7nzhA2
public void logResponseHead(HttpURLConnection con) 0j^Kgx
{ B`EJb71^Xy
for(int i=1;;i++) Lc}LGq!
{ T6'^EZZY
String header=con.getHeaderFieldKey(i); N:^n('U&j
if(header!=null) kXViWOXU^
//responseHeaders.put(header,httpConnection.getHeaderField(header)); EfqX y>W
Utility.log(header+" : "+con.getHeaderField(header)); N"Z{5A
else 2IK}vDsis
break; %U/(|wodd
} &j;wCvE4+
} ez7A4>/
2_>N/Z4T
{4l8}w
public void splitterStop() _?nL+\'V
{ ${DUCud,kY
bStop = true; QRw"H 8nW
} VMZMG$C
sWhZby7
xH ]Ct~md
} )L? P}$+
,Co|-DYf}
!M(xG%M-V
/* [DuttFX^x
**FileAccess.java :'Vf g[Uq
*//文件访问(定位，写) BT !^~S%w
package NetFox; TP*hd
import java.io.*; vz&|J
?4YGT
]U+LJOb
public class FileAccessI implements Serializable{ IW5,7.
,CJWO bn3
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 "69s)~
RandomAccessFile oSavedFile; t5Sy V:fP
long nPos; KS+'|q<?w
/WcG{Wdp
!t"4!3
public FileAccessI() throws IOException Z{*\S0^ST
{ & l<.X
this("",0); YP oSRA L
} aj='b.2)
&$+AXzn
,~U>'&M;
public FileAccessI(String sName,long nPos) throws IOException !|(-=2`
{ 1er TldX
oSavedFile = new RandomAccessFile(sName,"rw"); 3l~^06D
this.nPos = nPos; KYm0@O>;
oSavedFile.seek(nPos); &C_j\7Dq
} cVv=*81\
`bq<$e
U gat1Pz
public synchronized int write(byte[] b,int nStart,int nLen) g&L!1<, p
{ 70?\ugxA
int n = -1; Z-%\ <zT
try{ ic:zsuEm
oSavedFile.write(b,nStart,nLen); b`Zx!^
n = nLen; lf|FWqqV
} 'ms-*c&
catch(IOException e) }rUN_.n4z
{ `7E;VL^Y1
e.printStackTrace (); T=DbBy0-
} ^dWa;m]l
jVe1b1rt~3
bL`TySX
return n; LENq_@$
} bIDj[-CDG
_;S-x
>NV@R&
} zaIKdI'/e
fUWG*o9
,Zx0%#6
/* z_$%-6
**SiteInfoBean.java Y(ykng
*/ 6GlJ>r+n
package NetFox; RMV/&85?y
Qp5VP@t
;+R&}[9,A)
public class SiteInfoBean { ma]F7dZ5
B3`5O[6
{lzWrUGO
private String sSiteURL; //Site's URL gx/,)> E.
private String sFilePath; //Saved File's Path =ZznFVJ`={
private String sFileName; //Saved File's Name dES"@?!^
private int nSplitter; //Count of Splited Downloading File Evq IcZ
J[|y:N
y-b%T|p9
public SiteInfoBean() 1s&zMWC
{//nSplitter的缺省值为5 k9R4Y\8P
//default value of nSplitter is 5 yWc$>ne[L
this("","","",5); tKuwpT1Qc
} "S]0
9<?M8_
oSKXt}sh
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) 2RX;Ob_
{ }-{H Y
sSiteURL= sURL; 8NJqV+jn)t
sFilePath = sPath; oCv.Ln1;Z
sFileName = sName; t>RY7C;PuS
this.nSplitter = nSpiltter; C==hox7b
net@j#}j-
&m7]v,&
} Xu'&ynID
8FK/~,I
P`+{@@
public String getSSiteURL() H2 {+)
{ u~:y\/Y6
return sSiteURL; 05#1w#i
} PdFKs+Z`
1-uxC^u?|#
m9WDT
public void setSSiteURL(String value) &ywPuTt
{ ~Ffo-Nd-
sSiteURL = value; :RTC!spy
} (,\+tr8r8
>>)b'c
qr^3R&z!}
public String getSFilePath() ZQsJL\x[UK
{ 1=c\Rr9]
return sFilePath; ZU4nc3__
} ,-c6dS
re?,Wext\
IPKbMlV#d
public void setSFilePath(String value) f*% D$Mqg
{ SM#]H-3
sFilePath = value; i>A s;*
} I*{nP)^9
T*Exs|N2P-
LmrfN?5
public String getSFileName() myQagqRx
{ 5lmHotj#
return sFileName; kCF>nt@
} dq6m>;`
_/$Bpr{R
(N6i4 g6
public void setSFileName(String value) kZ .gO
{ }'V5/>m[
sFileName = value; [PM2\#K
} (Z q/
jD]~ AwRJ
6I4\q.^qw
public int getNSplitter() ]@c+]{
{ ^ogt+6c
return nSplitter; GW@;}m(
} YUD`!C
BO;tCEV?
D,*3w'X!K
public void setNSplitter(int nCount) rQs)O<jl
{ 8 +/rlHp
nSplitter = nCount; [A~xy'T
} ]NY~2jmX
} -#[a7',Z;
6dt]`zv/
6Q@j
/* FaSf7D`C
**Utility.java $y&E(J
*/ BwGfTua
package NetFox; (O?.)jEW(.
d#Y^>"|$.
rSk>
public class Utility { 29"'K.r
W~;`WR;.
Lc,Pom
public Utility() ~9]hV7y5C
{ .Wj;%|
B$ PP&/
"@@u3`#
} &< `NT D
?0?#U0(;u
//线程睡眠 QB uMJm
public static void sleep(int nSecond) Ad8n<zt|
{ wLH>:yKUU
try{ bKY7/w<dP
Thread.sleep(nSecond); gIa+5\qYY
} )3}9K ^jS
catch(Exception e) ZRB)uA)5=
{ ->-KCd1b
e.printStackTrace (); H3^},.
} n8 i] z
} @7]yl&LZ
!8d{q)JZ
//日志 ["93~[[^
public static void log(String sMsg) ? 7n`A >T
{ =_2jK0+}l
System.err.println(sMsg); ,t?B+$E
} k8[n+^
mbxZL<ua
h$>-.-
public static void log(int sMsg) 9gDkTYkj
{ b\kdKVh&
System.err.println(sMsg); D6Ui!
} f!uwzHA`?
} TH&U j1
_Xc8Yg }`
+>{2*\cZ5}
/* jh%Eq+#S
**TestMethod.java x(6SG+Kr
*/ Smn;(K
package NetFox; A@[o;H}XP
@ $ ;q;
]d0BN`*U.
public class TestMethod { ^R7lom.
]Idk:et
:'-/NtV)o?
public TestMethod() ?%-DfCS
{ ///xx/weblogic60b2_win.exe D9=KXo^
try{ t7Iv?5]N
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); HZC"nb}r4
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); x.!V^HQSN
SiteFileFetch fileFetch = new SiteFileFetch(bean); ZF9z~9
fileFetch.start(); ]?kZni8j_
} ghG**3xr
catch(Exception e){e.printStackTrace ();} {j?FNOJn
xQ-<WF1i
B$fPgW-
} $aDVG})
Q:G4Z9Kt
'4+ ur`
public static void main(String[] args) {9&;Q|D z
{ !Y0Vid
new TestMethod(); DrUO-
} i(%W_d!
} /tx]5`#@7]
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