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)); S@7A)
} {Pg7IYjH
for(int i=0;i<nEndPos.length-1;i++) cuR|cUK
{ j>s%q.
nEndPos = nStartPos[i+1]; ryx<^q
} kkrQ;i)Z
nEndPos[nEndPos.length-1] = nFileLength; %'* |N[
} ?XGZp?6
} ;8g#"p*&
hP,1;`[1
-JZl?hY(
//启动子线程 nwN<Q\]S
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; l:HO|Mq
for(int i=0;i<nStartPos.length;i++) ^B& Z
{ mc(&'U8R0I
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), O|j5ulO}&"
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), 3Uag[ms
nStartPos,nEndPos,i); &r<<4J(t
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); ]V@!kg(p8
fileSplitterFetch.start(); l}(~q!r
} jgbw'BBu
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), fJE ki>1
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); <tF]>(|M
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", Ky nZzR
nEndPos = " + nFileLength); )X^nzhZ2O"
// fileSplitterFetch[nPos.length-1].start(); Ya9uu@F
Zc9 n0t[
u khI#:[
//等待子线程结束 )cqhbR
//int count = 0; LOida#R
//是否结束while循环 aYj3a;EmU
boolean breakWhile = false; x(b&r g.-0
v8%]^` '
#Y18z5vo
while(!bStop) 2s{yg%U(
{ <01B\t7
write_nPos(); tIr66'8
Utility.sleep(500); D9LwYftZ
breakWhile = true; ,OasT!Sr
H7SqM D*y9
Xj-3C[8@
for(int i=0;i<nStartPos.length;i++) kcYR:;y
{ +bO{UC[
if(!fileSplitterFetch.bDownOver) T]vD ,I+
{ *Cb(4h-
breakWhile = false; @P.l8|w
break; So8P8TCK
} ^2??]R&Q
} ]Pd*w`R
if(breakWhile) e.jgV=dT-
break; 8@qahEgQ
gvU6p[D
vv8$u3H
//count++; FCe503qND$
//if(count>4) N4Lk3]
// siteStop(); OKU P
} Fu`g)#Z
PLY7qMw
JIQzP?+?
System.err.println("文件下载结束！"); 7uDUZdJy
} ;|^fAc~9{r
catch(Exception e){e.printStackTrace ();} RTU:J67E
} ,\m c.80
fBF}-{VX(
g<C})84y3
//获得文件长度 5[R}MhLZ
public long getFileSize() uJO*aA{K
{ a@a1/3
int nFileLength = -1; #X8[g_d/
try{ .Sn1YAhE
URL url = new URL(siteInfoBean.getSSiteURL()); xn@jL;+<-
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); MQ+ek4
httpConnection.setRequestProperty("User-Agent","NetFox"); 9C.cz\E
l>iU Q&V
pE<' '`
int responseCode=httpConnection.getResponseCode(); 7h<K)aT
if(responseCode>=400) ?4Lo"igAA
{ xH0/R LK3J
processErrorCode(responseCode); <D^x6{}
return -2; //-2 represent access is error :1=?/8h
} >H1d9y+Z
(wfg84
c`.:"i"k3
String sHeader; C;5}/J^E
ah92<'ix
M($},xAvDU
for(int i=1;;i++) LZVO9e]
{ 8zCAy@u
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); #r:`bQ0;
//Utility.log(in.readLine()); _:L*{=N
sHeader=httpConnection.getHeaderFieldKey(i); =I(s7=Liu
if(sHeader!=null) 5dF=DCZ
{ ,gvX ~k
if(sHeader.equals("Content-Length")) l)8V:MK
{ *K(xES!b
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); XbC8t &Q],
break; yFt7fdl2
} C\^K6,m5
} ;$QJnQ"R
else WGmCQE[/c
break; aK{\8L3]
} Bkc-iC}F
} [q&J"dt
catch(IOException e){e.printStackTrace ();} dx}/#jMa
catch(Exception e){e.printStackTrace ();} l8-jFeeMd
1l_}O1
F47n_JV!d
Utility.log(nFileLength); .6NSt
=]a@)6y
0UJ`<Bfd
return nFileLength; ~ ""MeaM8[
} _6!/}Fm
1Q SIZoK7
>!1f`
//保存下载信息（文件指针位置） 0JNOFX
private void write_nPos() a*j <TR
{ _oTT3[7P
try{ xbC8Amo;8"
output = new DataOutputStream(new FileOutputStream(tmpFile)); ?(q*U!=
output.writeInt(nStartPos.length); //lZmyP?
for(int i=0;i<nStartPos.length;i++) }+ 2"?f|]
{ /K) b0QX
// output.writeLong(nPos); cWO )QIE
output.writeLong(fileSplitterFetch.nStartPos); _[i=TqVmf
output.writeLong(fileSplitterFetch.nEndPos); 9*;isMkq<
} \>Rwg=Lh
output.close(); S7ehk*`
} ]HV~xD7\
catch(IOException e){e.printStackTrace ();} u)`|q_y+8
catch(Exception e){e.printStackTrace ();} g[au-.:
} Kxc$wN<
:.o=F`W
o U}t'WU
//读取保存的下载信息（文件指针位置） K#UA M.
private void read_nPos() &JhIn%=-
{ 3>9dJx4I
try{ pq?[wp"
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); OF<n T
int nCount = input.readInt(); fsJTwSI["
nStartPos = new long[nCount]; 5u)^FIBj
nEndPos = new long[nCount]; m0\"C-Bk
for(int i=0;i<nStartPos.length;i++) $^=jPk]+
{ 9Ir~X|}\iL
nStartPos = input.readLong(); V> a3V'
nEndPos = input.readLong(); ~|Ih JzDt
} df4^C->:
input.close(); ys[i`~$
} m0A@jWgd
catch(IOException e){e.printStackTrace ();} 9[p}.9/
catch(Exception e){e.printStackTrace ();} Wqs.oh
} t6bWSz0
M,\|V3s
B`Or#G3ph
private void processErrorCode(int nErrorCode) ay:\P.`5)
{ bOxjm`B<
System.err.println("Error Code : " + nErrorCode); TtwJ,&b
} iTugvb
UQ$\ an'
RM^?&PM85
//停止文件下载 Z;Ir>^<
public void siteStop() X[~f:E[1J
{ v[,v{5b
bStop = true; >|_gT%]5
for(int i=0;i<nStartPos.length;i++) HV*:<2P%D
fileSplitterFetch.splitterStop(); (ciGLfNG
1FD7~S|
0K$WSGB?6j
} g`)/x\
} A| gs Uh
//负责部分文件的抓取 do=x9k@Q
**FileSplitterFetch.java ,WO%L~db
*/ 2w x[D
package NetFox; 2pxWv )0
r>@ B+Xi
U9@t?j_#X{
import java.io.*; Jm]]>K8.3V
import java.net.*; , `[Z`SUk`
kH>vD =q>
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public class FileSplitterFetch extends Thread { 33{;[/4
2rR@2Vsw2
e-%7F]e
String sURL; //File URL )T.pjl
long nStartPos; //File Snippet Start Position q19k<BqR
long nEndPos; //File Snippet End Position =A0"0D{\
int nThreadID; //Thread's ID ONr?.MJ6j
boolean bDownOver = false; //Downing is over u n?j
boolean bStop = false; //Stop identical {UX"Epd);n
FileAccessI fileAccessI = null; //File Access interface 0^<Skm27"
d$"G1u~%
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public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException dl*_ m3T
{ EFa{O`_@U
this.sURL = sURL; i$`|Y*
this.nStartPos = nStart; ?VMi!-POE
this.nEndPos = nEnd; _SMT.lG
nThreadID = id; QmWC2$b
fileAccessI = new FileAccessI(sName,nStartPos);//定位 L?3VyBE
} ^w;o\G
} D/+<
1?D8|<
public void run() `!UaScM
{ &K9VEMCEX
while(nStartPos < nEndPos && !bStop) .;<7424(%
{ s0C?Bb}?
) >>u|#@z
bjM-Hd/K
try{ v?Z'[l
URL url = new URL(sURL); x\Nhix}1D
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); #W>x\
httpConnection.setRequestProperty("User-Agent","NetFox"); hrJ$%U
String sProperty = "bytes="+nStartPos+"-"; X)FL[RO%q
httpConnection.setRequestProperty("RANGE",sProperty); Du)B9s
Utility.log(sProperty); .K $p`WQ{
vqrBRlZ
T5K-gz7A
InputStream input = httpConnection.getInputStream(); pj!k|F9
//logResponseHead(httpConnection); EHH|4;P6
$?H]S]#|}.
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byte[] b = new byte[1024]; TZ^{pvBy
int nRead; Ix( 6
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) rDpe_varA
{ o8w-$ Qb
nStartPos += fileAccessI.write(b,0,nRead); X tJswxw`K
//if(nThreadID == 1) l0gH(28K
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); zSEr4^Dk4
} bZxv/\
b2a'KczV
IetCMp
Utility.log("Thread " + nThreadID + " is over!"); r`?&m3IOP
bDownOver = true; t@X M /=d
//nPos = fileAccessI.write (b,0,nRead); DY$yiOH9
} `ffj8U
catch(Exception e){e.printStackTrace ();} -sP9E|/:'3
} @[n2dmj
} -s{R/6:
kJ/+IGV^v
OlIT|bzkb
//打印回应的头信息 g* %bzfk=|
public void logResponseHead(HttpURLConnection con) 6!*K/2:O
{ |p;4dL
for(int i=1;;i++) !$xzAX,
{ 1Pu ,:Jt
String header=con.getHeaderFieldKey(i); 2q12yY f
if(header!=null) x<8\-
//responseHeaders.put(header,httpConnection.getHeaderField(header)); Lt>?y&CcQ
Utility.log(header+" : "+con.getHeaderField(header)); yU> T8oFh
else /#29Y^Z)=
break; ]OUD5T
} wbBE@RU>!
} ki#y&{v9Be
SzRL}}I
t/A:k
public void splitterStop() GX7VlI[
{ VZ;@S3TS
bStop = true; !5NGlqEF#
} xOhRTxic
D4d]3|/T
%@>YNPD`E
} yz2(_@R
\Ph]*%
D^N[=q99&e
/* ehU"*9
**FileAccess.java eVTO#R*'|
*//文件访问(定位，写) T{ok +$w2
package NetFox; 9wzwY[{
import java.io.*; wtq,`'B
Vfb<o"BQk
5H~@^!7t
public class FileAccessI implements Serializable{ ^mAJ[^%
0Qt~K#mr/
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 h5j<u
RandomAccessFile oSavedFile; 9g96 d-
long nPos; $]Jf0_
YjX*)Q_sl?
D6Dn&/>Zp
public FileAccessI() throws IOException [~t yDLC
{ ,|A{!j`
this("",0); f7ZA837Un
} <W?WUF
!F-sA: xq
whw{dfE
public FileAccessI(String sName,long nPos) throws IOException s_TD4~ $
{ W5|j1He&
oSavedFile = new RandomAccessFile(sName,"rw"); yYg
this.nPos = nPos; SijS5irfk
oSavedFile.seek(nPos); M= atls
} )}quw"H
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h>| g2h
public synchronized int write(byte[] b,int nStart,int nLen) QsM*wT&aa
{ eJW[ ]!
int n = -1; Jb9F=s+
try{ 1c/ X
oSavedFile.write(b,nStart,nLen); zx7#)*
n = nLen; Hl/7(FJqc>
} j!7Qw 8
catch(IOException e) ">cqt>2 A
{ G@B*E%$9
e.printStackTrace (); d[S#Duz<&
} Vli3>K&
.x>HA^4
!:dL~n
return n; i_NJ -K
} *Er? C;
+ LS3T^
A*Rn<{U
} <>n9'i1
EDtCNqBS~2
}s(C^0x
/* P,U$ %C!
**SiteInfoBean.java m9woredS,
*/ GY9y9HNZ
package NetFox; S*xhX1yUi
)@_ugW-j
4~*Y];!Q
public class SiteInfoBean { %Lyz_2q A
"9ue76
L_k9g12
private String sSiteURL; //Site's URL _[F@1NJ
private String sFilePath; //Saved File's Path r^Y~mq
private String sFileName; //Saved File's Name M7vj^mt?
private int nSplitter; //Count of Splited Downloading File 9qre|AA
IkU|W3Vo
D'nL
public SiteInfoBean() uOre,AQR
{//nSplitter的缺省值为5 kN.B/itvA
//default value of nSplitter is 5 rnH}#u+
this("","","",5); f1J%]g!
} YmgCl!r@
G5;V.#"Z[
xDUaHE1co
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) {>h97}P
{ pC^2Rzf
sSiteURL= sURL; _ eiF@G
sFilePath = sPath; kW+G1|
sFileName = sName; t!0dJud
this.nSplitter = nSpiltter; cQn)^jx=
{xToz]YA
$_FZn'Db6
} }[v~&
fhr-Y'
;s}3e#$L
public String getSSiteURL() B2(,~^39
{ GI_DhU]~)
return sSiteURL; +Vy_9I(4Z
} d;44;*D
fI]bzv;
S=PJhAF
public void setSSiteURL(String value) !F$R+A+L
{ UJn/s;$.e
sSiteURL = value; I7zn>^0}
} /AR]dcL@76
"Yby
0m&3?"5u
public String getSFilePath() \igaQ\~
{ `pm>'
return sFilePath; pX_b6%yX(
} v ):V
>|nt2
HTR1)b
public void setSFilePath(String value) 7xT[<?,
{ l"5y?jT
sFilePath = value; agT7=hX].
} {i;6vRr
N"1QX6
]EN&SWh
public String getSFileName() uA%Ts*aN
{ EY$?^iS
return sFileName; u]bz42]
} sUciFAb
ox4W$YdMG
L[]BzsIv
public void setSFileName(String value) VYigxhP7
{ |X3">U +-
sFileName = value; mPG7Zy$z
} fnOIv#
n1 v,#GE
DqlK.
public int getNSplitter() }# Xi`<{
{ I.a0[E/,
return nSplitter; HfZtL
} j ug'g
liD47}+
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public void setNSplitter(int nCount) Sn ^Aud
{ ,LZ(^u
nSplitter = nCount; jsdBd2Gdc
} "5|\X<f
} VVLIeJ(*XT
vgo{]:Aj{
?K<ZkYw?
/* ^aptLJF
**Utility.java ^IgS
*/ u~}%1
package NetFox; b0YNac.l
Yrsp%<qj
Qc3?}os2
public class Utility { 50,Y
Ut_mrb+W
S.hC$0vrj
public Utility() 9GPb$gtx
{ !sG"n&uZq
_.=`>%,
-#%X3F7/w
} ~d>uXrb
lM+ xU;
//线程睡眠 ns26$bU
public static void sleep(int nSecond) gIBpOPr^d
{ Q"'V9m7 i
try{ eE9|F/-L
Thread.sleep(nSecond); eJ:Yj ~X`<
} /x/4NeD
catch(Exception e) oAnigu;
{ R'Eq:Rv~;^
e.printStackTrace (); F"=Hp4-C
} 4,zvFH*AH
} phS>T
3KT_AJ4}
//日志 H|K("AVP:
public static void log(String sMsg) 4Cd#sQ
{ cUsL6y
System.err.println(sMsg); Xy!&^C` J`
} @p6@a6N%
B0"0_n7-
mmcdtVe
public static void log(int sMsg) WvbEh|y
{ V&R$8tpz
System.err.println(sMsg); Pxk0(oBX
} C d|W#.6
} |K)p]i+
4(8<w cL
5}7ISNP;f
/* |=u96G~N
**TestMethod.java W]@6=OpH
*/ {=6)SBjf
package NetFox; Ysl9f1>%
3t*#!^$
44j,,k
public class TestMethod { 5pmQp}}R
D>Ua#<52q
'{CWanTPi
public TestMethod() .8x@IWJD
{ ///xx/weblogic60b2_win.exe M=6G:HHY
try{ MISE C[/
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); ZqFUPHc
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); Y!it!9
SiteFileFetch fileFetch = new SiteFileFetch(bean); dxntGH< O
fileFetch.start(); 4@mso+tk
} )gjGG8Ee
catch(Exception e){e.printStackTrace ();} N"K\ick6J
",QPb3
q#|r
} XR<G}x
Qi"'bWX@
^F&A6{9f/h
public static void main(String[] args) El+Ft.7
{ (Wn "3 ]
new TestMethod(); 97(n\Wt2
} @f%wd2
} SKW;MVC
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