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)); e. E$Ej]w
} Kv#Q$$)r
for(int i=0;i<nEndPos.length-1;i++) `nc=@" 1
{ fN9uSnu
nEndPos = nStartPos[i+1]; TIF =fQ
} e#WASHZN
nEndPos[nEndPos.length-1] = nFileLength; OL@$RTh
} {"rL3Lk
} zqRps8=
^ 7)H;$
|f$gQI!XW
//启动子线程 ]9wTAb
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; ogV v 8Xb
for(int i=0;i<nStartPos.length;i++) |F qujZz
{ ?dk)2
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), ,WAJ& '^
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), [EQTrr( D
nStartPos,nEndPos,i); rV*Ri~Vx
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 9pk-#/ag
fileSplitterFetch.start(); s>{\^T7y
} zOy_qozk
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), R[QBFL<
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); )L_@l5l
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", /U6ry'
nEndPos = " + nFileLength); tvUCd}
// fileSplitterFetch[nPos.length-1].start(); vJX0c\e
e YiqTWn:
'HL.W](
//等待子线程结束 $wl_
//int count = 0; '+*'sQvH[
//是否结束while循环 x}{O9LiR
boolean breakWhile = false; sy6[%8D$
c68,,rJO]i
i\#?M "
while(!bStop) r=]$>&
{ L_M(Lj
write_nPos(); [<jU$93E
Utility.sleep(500); Yq{R*HO
breakWhile = true; 8RS@YO
@R`Ao9n9V
0])[\O`j
for(int i=0;i<nStartPos.length;i++) 8}Q2!,9Q
{ Q0g^%
if(!fileSplitterFetch.bDownOver) S2#@j#\
{ aeEio;G1
breakWhile = false; R\x3'([A5
break; #f_.
} F^?DnZs
} E7I$GD
if(breakWhile) m+x$LkP
break; [&lH[:Y#
g]d0B!Ar~
>^ E*7Bfp
//count++; 0Ld"df*
//if(count>4) j&q%@%Gm
// siteStop(); =i},$"Bf*%
} | _nBiHjNn
K :>O X
e^N}(Kpy
System.err.println("文件下载结束！"); 0="wxB
} {??bJRT
catch(Exception e){e.printStackTrace ();} ezS@`_pR;
} N).'>
X]=8Oa
RxVZn""
//获得文件长度 u7},+E)+B
public long getFileSize() WfYG#!}x
{ N%)q.'M
int nFileLength = -1; l;B
try{ `(E$-m-~jH
URL url = new URL(siteInfoBean.getSSiteURL()); ,G[Y< ~Hy
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); a&7uRR26
httpConnection.setRequestProperty("User-Agent","NetFox"); VDiW9]
&7r a
b&9~F6aM
int responseCode=httpConnection.getResponseCode(); OMBH[_
if(responseCode>=400) x }]"jj2x
{ W<$!H V$
processErrorCode(responseCode); |FSp`P
return -2; //-2 represent access is error F'T.-lEO_d
} X3?RwN:P
Zb:Z,O(vn
D[Q/:_2l
String sHeader; 2G_]Y8
/-+hMYe
7j88^59
for(int i=1;;i++) Z,V<&9a;
{ K87yQOjPv
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); F?qg?1vB|
//Utility.log(in.readLine()); RNt9Qdr4y
sHeader=httpConnection.getHeaderFieldKey(i); '($$-P\/
if(sHeader!=null) %l!-rXp
{ ZVrZkd`
if(sHeader.equals("Content-Length")) fm!\**Q1
{ |OuIQhoE
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); ZX'3qW^D
break; `^|l+TJG
} 20I/En
} e`Co ='
else Of}C.N8
break; ?P/73p
} 7R5+Q\W
} e$&n)>%
catch(IOException e){e.printStackTrace ();} 5<P6PHdY
catch(Exception e){e.printStackTrace ();} *U`R<mV\
LCuz_LTFq{
2rb@Md]dx
Utility.log(nFileLength); [GcW*v
yq[@Cw
ZH~Wn#Wp
return nFileLength; DcE4r>8B
} |7${E^u
8\jsGN.$JZ
&=XK:+
//保存下载信息（文件指针位置） k *>"@
private void write_nPos() 7xfS%'=y"
{ 3$.#\*s_4
try{ \s!x;nw[
output = new DataOutputStream(new FileOutputStream(tmpFile)); pF(6M3>IN
output.writeInt(nStartPos.length); #$F*.vQSs+
for(int i=0;i<nStartPos.length;i++) kdaq_O:s
{ M`E}1WNQ?]
// output.writeLong(nPos); 1MmEP
output.writeLong(fileSplitterFetch.nStartPos); Qj$w7*U
output.writeLong(fileSplitterFetch.nEndPos); wJ"]H!r0
} nj1PR`AE
output.close(); 3eB)X2~
} p|@#IoA/e
catch(IOException e){e.printStackTrace ();} fB]NEx|o~
catch(Exception e){e.printStackTrace ();} CTxP3a9]
} {qOqtkj
CyXaHO
}Yc5U,A;
//读取保存的下载信息（文件指针位置） lQy-&d|=#^
private void read_nPos() |kTq &^$
{ WBb*2
try{ +r&:c[
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); /y6I I$AvM
int nCount = input.readInt(); S#<y_w%
nStartPos = new long[nCount]; JoZSp"R
nEndPos = new long[nCount]; ;lfv.-u:<
for(int i=0;i<nStartPos.length;i++) :Gew8G
{ 12;YxW>[
nStartPos = input.readLong(); )uMv]
nEndPos = input.readLong(); UcH#J &r
} [ako8
input.close(); wvxsn!Ao&=
} ;>S|?M4GZ
catch(IOException e){e.printStackTrace ();} Q7i(M >|O
catch(Exception e){e.printStackTrace ();} be$']}cP
} 9A/bA|$
9%bErMHL
*LuRo
private void processErrorCode(int nErrorCode) 4C;y2`C
{ Kr;=4xg=
System.err.println("Error Code : " + nErrorCode); G*jq5_6
} +L@\/=;G
<lLJf8OK
M?GkHJ%!
//停止文件下载 R1eWPtWs
public void siteStop() z^s\&gix
{ USS%T<Vk
bStop = true; ]Qa|9G,b
for(int i=0;i<nStartPos.length;i++) WW2hwB(
fileSplitterFetch.splitterStop(); i0J`{PbI
:,g]Om^
sZEa8
} B9%%jEH*
} dZI["FeO&d
//负责部分文件的抓取 ^@{"a
**FileSplitterFetch.java *u",-n
*/ <]X6%LX
package NetFox; 9X +dp
FFN Sn
L./c#b!{
import java.io.*; g-1j#V`5
import java.net.*; \CVHtV
Xo&\~b#-
"a3?m)
public class FileSplitterFetch extends Thread { H8=:LF
!l Egta[Ql
F^aD#
String sURL; //File URL WtaOf_
long nStartPos; //File Snippet Start Position `j!_tE`
long nEndPos; //File Snippet End Position y7%SHYC p[
int nThreadID; //Thread's ID 9NNXj^7
boolean bDownOver = false; //Downing is over i5&,Bpfo-
boolean bStop = false; //Stop identical $EEn]y
FileAccessI fileAccessI = null; //File Access interface ST;o^\B
`w`F-ke]I
=LKM)d=1
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException E|+<m!
{ %g{)K)$,ui
this.sURL = sURL; {cb<9Fii
this.nStartPos = nStart; ;r&Z?B$
this.nEndPos = nEnd; s9OW.i]zX
nThreadID = id; 4nQ5zwiV
fileAccessI = new FileAccessI(sName,nStartPos);//定位 M ?AX:0
} 1ltW9^cF}
p>#q* eU5
DEt!/a{X
public void run() K+XUC
{ %5DM ew
while(nStartPos < nEndPos && !bStop) e-[PuJ
{ SynRi/BRmw
qxsHhyB_n;
BW}M/
try{ r4DHALu#)
URL url = new URL(sURL); qvK/}
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); !n P4S)A
httpConnection.setRequestProperty("User-Agent","NetFox"); Q\T?t
String sProperty = "bytes="+nStartPos+"-"; ^8J`*R8CL
httpConnection.setRequestProperty("RANGE",sProperty); 6EO@Xf7,
Utility.log(sProperty); VX>j2Z'
6x=w-32+ y
nMfR<%r
InputStream input = httpConnection.getInputStream(); }6<5mq)%
//logResponseHead(httpConnection); [u37Hy_Gi
6-0sBB9=u
BV }CmU&DA
byte[] b = new byte[1024]; ] $r].,&
int nRead; yT5OFD|T
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) yU4mS;GX
{ }.Z`
nStartPos += fileAccessI.write(b,0,nRead); 9V[}#(f$
//if(nThreadID == 1) gIusp917
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 0@{0#W3R
} *Uj;a.
k0#s{<I]E
h]+;"v6 /
Utility.log("Thread " + nThreadID + " is over!"); \E<Qi3W>*
bDownOver = true; i/H;4#Bz
//nPos = fileAccessI.write (b,0,nRead); H(P]Z~et
} >]xW{71F@
catch(Exception e){e.printStackTrace ();} hITYBPqRO
} 1 ] cLbJ
} .4tu{\YX
P:N>#G~z
FfrC/"N
//打印回应的头信息 t[|t0y8
public void logResponseHead(HttpURLConnection con) <hiv8/)?
{ ViMl{3
for(int i=1;;i++) aq8./^
{ UnP<`z#
String header=con.getHeaderFieldKey(i); D,[Nn_N
if(header!=null) ]'M B3@T
//responseHeaders.put(header,httpConnection.getHeaderField(header)); ]Y!Fz<-;P
Utility.log(header+" : "+con.getHeaderField(header)); \w>Rmf'|
else .P/0`A{&
break; Ui"{0%
} _q4O2Fx0
} $/tj<++W
eq(h{*rC
1"75+Q>D
public void splitterStop() WFFQxd|Z
{ ~:o$}`mW
bStop = true; 'SoBB:
} 5`+9<8V
>1;jBx>Qy%
]+3M\ ib
} C;K+ITlJ
7pQ5`;P
c%^B '
/* \k`9s q
**FileAccess.java unew XHA
*//文件访问(定位，写) |N"K83_pr
package NetFox; W Zm8!Y
import java.io.*; czpu^BT;;T
}2"W0ZdWD
w0oTV;yh
public class FileAccessI implements Serializable{ CEaAtAM
E;x-O)(&
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 , QWus"5H
RandomAccessFile oSavedFile; W02z}"#
long nPos; v<g=uEpN
l~f3J$OkJ
oYTLC@98}
public FileAccessI() throws IOException ~%g,Uypi
{ ,d38TN
this("",0); zIu/!aw
} *jWh4F,
f$kbb6juL
G'#u!<(^h
public FileAccessI(String sName,long nPos) throws IOException fRLA;1va
{ +hr|$
oSavedFile = new RandomAccessFile(sName,"rw"); l!Xj UnRF
this.nPos = nPos; +~aIT=i3
oSavedFile.seek(nPos); `PL}8ydZ
} N>"L2E=z$|
Z_4%Oi
*AW v
public synchronized int write(byte[] b,int nStart,int nLen) fW+"Kuw
{ {d;z3AB
int n = -1; a{Y|`*7y
try{ 3en67l
oSavedFile.write(b,nStart,nLen); l5Ko9CG
n = nLen; aF+Lam(
} [J}eNprg
catch(IOException e) ?HZ^V
{ Y z&!0Hfd
e.printStackTrace (); d7[^pN
} 1G5AL2
G~(\N?2
t,JX6ni
return n; R@z`
} 2p\xgAW?
wn!=G~nB
J8r8#Zz
} E>tHKNyVTp
JfSe; v
ox&?`DO
/* eS@j? Y0y
**SiteInfoBean.java M.}J SDt
*/ kBcTXl
package NetFox; ]bh%pn
cl`Wl/Q#
>.`*KQdan
public class SiteInfoBean { vr4r,[B6y
h+j^VsP zB
z{\tn.67
private String sSiteURL; //Site's URL `14@dk
private String sFilePath; //Saved File's Path }BI6dZ~2A
private String sFileName; //Saved File's Name y,|2hrj/0E
private int nSplitter; //Count of Splited Downloading File s9CmR]C
CZu=/8?
BQ Vro;#Jc
public SiteInfoBean() QJ(%rvn3
{//nSplitter的缺省值为5 =LV-n
//default value of nSplitter is 5 U!r8}@
this("","","",5); XK3O,XM
} ^O@eyP
B!x#|vGXL
l+P!I{n
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) b)KEB9w
{ `MPR-"Z6
sSiteURL= sURL; "q M
sFilePath = sPath; i56Rdb
sFileName = sName; FsWp>}o
this.nSplitter = nSpiltter; WVpx
Oj_]`
qna!j|90Lp
} )M+po-6$1
{!wW,3|Pu
HYGd :SeH
public String getSSiteURL() p:y\{k"
{ =O0A(ca"g
return sSiteURL; Vlz\n
} Lg!E
K=0xR*ll5
4sQm"XgE
public void setSSiteURL(String value) '=Zm[P,
{ DoQ^caa@
sSiteURL = value; ;6pB7N
} ):>?N`{V
k6ry"W3
YAT@xZs-
public String getSFilePath() 7,p.M)t)
{ ^Z9bA(w8
return sFilePath; Lr:n
} B//*hH >F
z/4<x?}+hE
Uvm.|p_V
public void setSFilePath(String value) I@Hx LEGj
{ iu8Q &Us0P
sFilePath = value; 96~y\X@x
} LJPJENtFIs
"zY~*3d
(BPp2^
public String getSFileName() ZwsQ}5
{ {v]L|e%{
return sFileName; B3&C&o.h
} ddKP3}
BT8)t.+pv
:s_.K'4?a
public void setSFileName(String value) : H;S"D
{ iE"]S )
sFileName = value; |}:}14ty
} &nr{-][
^P~,bO&H.Z
_|12BVq
public int getNSplitter() 8e>B>'nH
{ jXf@JxQ
return nSplitter; )e3w-es~4
} DmuQE~DV
p P@q `
i*:QbMb
public void setNSplitter(int nCount) rbdrs
{ @H#Fzoo.
nSplitter = nCount; ,}'8. f
} oH0g>E;
} jnOnV1I"
Lw[=pe0e
5\h 6"/6Df
/* Pv2uZH(
**Utility.java RN)XIf$@_
*/ r&a}U6k(y
package NetFox; Wfd`v
SF;\*]["f
fn 'n'X|
public class Utility { C=o-3w
,i}EGW,9q
)-5eIy
public Utility() )-[$m%
{ WZ6{9/%:
SS%Bde&<{
]N]Fb3
} 9FSa=<0wE
mB>0$l y
//线程睡眠 9HFEp-"
public static void sleep(int nSecond) PZ6R+n8
{ Q`8-|(ngw
try{ 98u@X:3
Thread.sleep(nSecond); e.MyJ:eL
} eC<RM Q4
catch(Exception e) sjLMM_'
{ OW};i|
e.printStackTrace (); Rl cL(HM
} +%9Re5R
} b`+yNf
Ix_w.f=8
//日志 k%~;mu"4}
public static void log(String sMsg) Bq)dqLwk
{ 4Us,DS_/
System.err.println(sMsg); In?+
} v=G*K11@
wX2U
o NA ]G]
public static void log(int sMsg) $S<B\\ %
{ /d|:
System.err.println(sMsg); i9Bh<j>:J
} j"~"-E(79
} ~{{S<S v
x#SE%j?
M.dX;iM<
/* ^g(qPtQ
**TestMethod.java o%j?}J7y
*/ C1_0 9Vc
package NetFox; [7PC\
fWA#n
>F7HKwg}Z
public class TestMethod { H%l-@::+$
C;:=r:bth
(=u!E+N
public TestMethod() bnkZWw'9
{ ///xx/weblogic60b2_win.exe *FEJ5x
try{ )=gU~UV
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); +p>h` fc
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); BhAT@%
SiteFileFetch fileFetch = new SiteFileFetch(bean); 2 ^"j]g>mj
fileFetch.start(); H0OO+MCe
} 1ED7.#g
catch(Exception e){e.printStackTrace ();} IfB .2e`
Z}0{FwW"4
M .6BFC
} qZ>_{b0f
TDk[,4
8 0nu^_
public static void main(String[] args) Zl9
{ T&/n.-@nk
new TestMethod(); cz/E
} Q{S{|.w-
} $LuU
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