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 V }+eU
} =RKSag&
for(int i=0;i<nEndPos.length-1;i++) bF-"tm
{ VaLs`q&3>
nEndPos = nStartPos[i+1]; E6A/SVp
} -x*2t;%z{U
nEndPos[nEndPos.length-1] = nFileLength; B\CN<<N>dD
} o\=n4;S
} HdX2YPYn;
bGmx7qt#
zm#nV Y`
//启动子线程 .\:J~(
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; L%\b'fs
for(int i=0;i<nStartPos.length;i++) 2A:,;~UH
{ wCKj7y[
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), uGVy6,
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), Da1aI]{I
nStartPos,nEndPos,i); I'!/[\_
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); MaY682}|y
fileSplitterFetch.start(); v"O5u%P
} '7)"
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), mUP.rb6
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); `V!>J1x
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", s8mr''
nEndPos = " + nFileLength); ajH"Jy3A
// fileSplitterFetch[nPos.length-1].start(); N#z~
cP>o+-)
~Y!kB:D5;~
//等待子线程结束 MuI2?:~:*4
//int count = 0; .*/Fucr
//是否结束while循环 E6MA?Ax&=
boolean breakWhile = false; 5.0e~zlM-
elPE%'
S::>N.y
while(!bStop) $)Bg JDr
{ \_BkY%a
write_nPos(); Ym8}ZW-
Utility.sleep(500); m`A% p
breakWhile = true; 5Av=3[kh"%
:k=mzO<&
gAbD7SE
for(int i=0;i<nStartPos.length;i++) A%bCMP
{ +9A\HQ|22
if(!fileSplitterFetch.bDownOver) obH;g*
{ 47>>4_Hz
breakWhile = false; aaW]JmRb
break; ~$,qgf
} 7/IlL
} 3iNkoBCg
if(breakWhile) @%ECj)u`O
break; f'Mop= .
,_ 2x{0w:>
K\?]$dK5
//count++; !36]ud&
//if(count>4) /Lf6WMit
// siteStop(); hpbf&S4
} PAF8Wlg
1Y j~fb(
gE7L L=x
System.err.println("文件下载结束！"); "&+3#D >
} b1?xeG#
catch(Exception e){e.printStackTrace ();} =d`5f@'rl
} t*S." q
/bRg?Q
Xl-e !
//获得文件长度 :l\V'=%9'@
public long getFileSize() :l u5Uu~
{ *ZCn8m:-+
int nFileLength = -1; _2ef LjXQ
try{ $.E6S<(h
URL url = new URL(siteInfoBean.getSSiteURL()); -G|a*^
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); P ,mN >
httpConnection.setRequestProperty("User-Agent","NetFox"); Gu0 ,)jy\
# TkR
3R$Z[D-
int responseCode=httpConnection.getResponseCode(); 'Prxocxq
if(responseCode>=400) Ri*3ySyb
{ 2[yBD-":
processErrorCode(responseCode); N:5[,O<m_
return -2; //-2 represent access is error |UUdz_i!:
} r?$?;%|C
w}cY6O,1
dl]#
String sHeader; W7No ls{
ki]ti={12
k ]a*&me
for(int i=1;;i++) 9)dfL?x8V{
{ $%k1fa C
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); $4=f+ "z
//Utility.log(in.readLine()); RVw9Y*]b
sHeader=httpConnection.getHeaderFieldKey(i); clO,}Ph>
if(sHeader!=null) uKr1Z2
{ SI:ifR&T
if(sHeader.equals("Content-Length")) 2][DZl
{ 4Ft1@
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); Ukz;0q
break; V4w=/e_
} Rd*[%)
} ~%k?L4%
else ~p1EF;4#
break; X@2-*so<
} k=ytuV\
} S::=85[>z
catch(IOException e){e.printStackTrace ();} \E1U@6a
catch(Exception e){e.printStackTrace ();} 32)tJ|m
QCOo
^rNUAj9Z
Utility.log(nFileLength); +C]&2zc.
j{++6<tr
?X$,fQ#F|
return nFileLength; giY80!GX
} }ut]\]b
<U Zd;e@
7L5P%zLtB
//保存下载信息（文件指针位置） D=f7NVc>Q
private void write_nPos() : esg(
{ z,SYw &S
try{ Y$>-%KcKeI
output = new DataOutputStream(new FileOutputStream(tmpFile)); bzpFbfb
output.writeInt(nStartPos.length); m!n/U-^
for(int i=0;i<nStartPos.length;i++) 3 fj
{ p/6zEZ*
// output.writeLong(nPos); S^I,Iz+`S'
output.writeLong(fileSplitterFetch.nStartPos); Dr<='Ux[5
output.writeLong(fileSplitterFetch.nEndPos); k`KGB
} <!d"E@%v@
output.close(); DbI!l`Vn4
} v5}X+'
catch(IOException e){e.printStackTrace ();} {lG@hN'
catch(Exception e){e.printStackTrace ();} Rfb?f}j
} hS [SRa'.
#Il_J\#
t0&@h\K
//读取保存的下载信息（文件指针位置） SuBeNA[&
private void read_nPos() IXLO>>`
{ EV M7Q>
try{ NcS.49
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); w42OF7f
int nCount = input.readInt(); UKd'+R]
nStartPos = new long[nCount]; 2.uA|~qH
nEndPos = new long[nCount]; B:TR2G9UT
for(int i=0;i<nStartPos.length;i++) @LE[ac
{ f7urJ'!V
nStartPos = input.readLong(); X?r48l??
nEndPos = input.readLong(); cV K7
} 0rSIfYZa
input.close(); \`.F\Z
} E8\XNG)V4
catch(IOException e){e.printStackTrace ();} -[7O7'
catch(Exception e){e.printStackTrace ();} #U7_a{cn"M
} )P&9A)8
y8Xv~4qQW
5i6 hp;=
private void processErrorCode(int nErrorCode) >B -q@D
{ AIl4]F5I
System.err.println("Error Code : " + nErrorCode); ~!iQ6N?PY
} B/f0P(7
}alj[)
<~emx'F|
//停止文件下载 }3 m0AQ;K
public void siteStop() FjfN3#qlg
{ 9W7#u}Z
bStop = true; j|fd-<ng
for(int i=0;i<nStartPos.length;i++) le)DgIT>=
fileSplitterFetch.splitterStop(); 8ip7^
|f( ~@Q:
|k 2"_
} )+y G+
} 8;P2A\X
//负责部分文件的抓取 7v}x?I
**FileSplitterFetch.java 1MsWnSvzf
*/ '!h/B;*(
package NetFox; 4Cb9%Q0
u^W2UE\
_,AzJ^
import java.io.*; E|EgB33S
import java.net.*; NW9n
?9MVM~$
10[Jl5+t
public class FileSplitterFetch extends Thread { yq[Cq=rBk
n| O [a6G
yqOuX>m1c
String sURL; //File URL e&q?}Ho
long nStartPos; //File Snippet Start Position l]!9$
long nEndPos; //File Snippet End Position '(+<UpG_Q}
int nThreadID; //Thread's ID 8y';\(;
boolean bDownOver = false; //Downing is over v`[Eb27W.
boolean bStop = false; //Stop identical N^0uit
FileAccessI fileAccessI = null; //File Access interface i8X`HbmN
;Q0bT`/X
=1;=
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException 9W`Frx'h1
{ NmIHYN3
this.sURL = sURL; B6P|Z%E;D6
this.nStartPos = nStart; V}w;Y?]J
this.nEndPos = nEnd; aT l c
nThreadID = id; M[5[N{
fileAccessI = new FileAccessI(sName,nStartPos);//定位 ks;%*d
} `\Ku]6J]5
.ae O}^
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public void run() S&jesG-F
{ S]3Ev#>
while(nStartPos < nEndPos && !bStop) R\Z:n*
{ NF$\^WvYSP
N[|Nxm0z/C
X~.f7Ao[
try{ &xZyM@
URL url = new URL(sURL); AN:@fZ
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); Pi2|
httpConnection.setRequestProperty("User-Agent","NetFox"); ;!@EixN-YH
String sProperty = "bytes="+nStartPos+"-"; =ziwxIo6
httpConnection.setRequestProperty("RANGE",sProperty); U!w1AY|
Utility.log(sProperty); nQK|n^AU/
>k7q g$
E .6HpIx
InputStream input = httpConnection.getInputStream(); 4A`NJ
//logResponseHead(httpConnection); -|yb[~3
AF,BwLN
HG>j5
byte[] b = new byte[1024]; wmr-}Y!9u%
int nRead; 4b]a&_-}
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) %~|HFYd
{ "%2xR[NF
nStartPos += fileAccessI.write(b,0,nRead); ~vdkFc(8B
//if(nThreadID == 1) W{cY6@
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); -_VG;$,jE
} }f>H\iJe
+ bhym+
)wXuwdc[
Utility.log("Thread " + nThreadID + " is over!"); CR<`ZNuWz
bDownOver = true; Mq%,lJA\
//nPos = fileAccessI.write (b,0,nRead); 7YWNd^FI V
} HHk)ZfWRo
catch(Exception e){e.printStackTrace ();} Y]aW)u
} `:{B(+6
} }*U[>Z-eO
0Sl]!PZR1
-5G)?J/*
//打印回应的头信息 96Wp!]*
public void logResponseHead(HttpURLConnection con) =;~I_)Pg1
{ 1{"llD
for(int i=1;;i++) ?z-}>$I;
{ ^>4o$}
String header=con.getHeaderFieldKey(i); OvL\u{(<F
if(header!=null) %rKK[
//responseHeaders.put(header,httpConnection.getHeaderField(header)); o@>? *=
Utility.log(header+" : "+con.getHeaderField(header)); ER&UBUu"
else t6N*6ld2b
break; q!'rz
} Z@D*1\TG=
} X+8B!F
|tMn={
/x@RNdKv
public void splitterStop() c2SC|s]
{ P3tx|:gV
bStop = true; G1T^a>tj4
} Q'apG)0I
8 }'|]JK
Nf,Z;5e
} VU|dV\>
jLg@FDb~
-#`c5y}P
/* "7%:sty
**FileAccess.java omZO+=8Q
*//文件访问(定位，写) -PB[-CX
package NetFox; [^H"FA[
import java.io.*; w&&2H8
'$|UwT`s
#>;FUZuJr
public class FileAccessI implements Serializable{ ]J1S#Q5'
ig"uXs
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 d=.2@Ry
RandomAccessFile oSavedFile; 3Q}$fQ&S
long nPos; !,$i6gm
^u)z{.z'H/
qf'm=efRyu
public FileAccessI() throws IOException uw\1b.r'B
{ #PLEPB
this("",0); Sywu=b
} 6x{<e4<n
Tz&Y]#h_
I lR\ #
public FileAccessI(String sName,long nPos) throws IOException ?gGt2O1J
{ yQS+P8x&|]
oSavedFile = new RandomAccessFile(sName,"rw"); <M?:
this.nPos = nPos; |Q~cX!;
oSavedFile.seek(nPos); 6bc337b
} ^:, l\Y
RH0>ZZR
c2l_$p
public synchronized int write(byte[] b,int nStart,int nLen) i yYJR
{ mbl]>JsQD
int n = -1; ,n,RFa
try{ jPvDFT^d/
oSavedFile.write(b,nStart,nLen); ]6Ug>>x5
n = nLen; \b8sG"G
} C=Fzu&N}
catch(IOException e) FaTa(3$%
{ ~Z/ ^c,[:
e.printStackTrace (); aAvsb$
} ,"-Rf<q/
S&nxok`e^
"tit\a6\(
return n; f}c\_}(
} ]-o"}"3Ef
<<A`aU^fX
IHfzZHy
} S&C1TC
l*b)st_p%
3q[WHwmm
/* l7(!`NPbC
**SiteInfoBean.java gCd`pi 8
*/ bSwWszd~
package NetFox; ({0)@+V8
OIHz I2{
?{"mP 'dD
public class SiteInfoBean { Nb2Qp K
9&%fq)gS
a\uie$"cr]
private String sSiteURL; //Site's URL /T^ JS
private String sFilePath; //Saved File's Path 5M]z5}n/
private String sFileName; //Saved File's Name ek aFN\
private int nSplitter; //Count of Splited Downloading File cR-~)UyrO
Ax3W2s
)Ag/Qep
public SiteInfoBean() (<t_Pru
{//nSplitter的缺省值为5 9ILIEm:
//default value of nSplitter is 5 tHD
this("","","",5); `+lHeLz':
} 6< J #^ 6
YO{GU7
$v.C0 x
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) 9_ICNG%
{ M/PFPJ >`
sSiteURL= sURL; $DFv30 f
sFilePath = sPath; QlFZO4 P3|
sFileName = sName; +YOKA*
this.nSplitter = nSpiltter; wCs3:@UH
7z6b@$,
ub0zJTFJ#
} k@>\LR/v
yDb'7(3-
vqslirC
public String getSSiteURL() P=L$;xgp
{ ;cQW sTfT
return sSiteURL; _,Fny_u=;
} _fFU#k:MU
1PaUI#X"2F
A\rt6/
public void setSSiteURL(String value) Q0?\]2eet9
{ gIWrlIV{9
sSiteURL = value; mAgF73,3
} L(;WxHL
,iNv'
U;_[b"SW%
public String getSFilePath() 4Ph0:^i_
{ vP%tk s+.
return sFilePath; &MmU
} Hi!Jj
LVIAF0kX
q:>^ "P{
public void setSFilePath(String value) &ej8mq"\
{ 3>ex5
sFilePath = value; Z.L?1V8Q1
} foF19_2 ,
>t,M
%1 KbS [
public String getSFileName() ?)Nj c&G
{ uaw~r2
return sFileName; o!TQk{0
} dCYCHHHF
Zt -1h{7
dBsX*}C
public void setSFileName(String value) h[KvhbD3
{ uy_wp^
sFileName = value; cxeghy:;U
} RT/o$$
oq/G`{`\
%\O#&=$E
public int getNSplitter() tary6K9K+
{ 3H\w2V
return nSplitter; 3FSqd<t;D
} g3n'aD@'x
m8Vdb"0
Y&H}xn
public void setNSplitter(int nCount) h-a!q7]l
{ rj]F87"
nSplitter = nCount; ))D:8l@
} .D,p@4
} gbOpj3
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(;x3} ]
/* <>eOC9;VY
**Utility.java KT|RF
*/ mpC`Yk
package NetFox; Ok5<TZ6t4k
iF5'ygR-Z
c:S] R"
public class Utility { W+wA_s2&D
5V[oE\B
ulT8lw='
public Utility() WFR?fDtE
{ l5%G'1w#,j
$w)~O<_U
MfO:m[s
} 7`vEe'qz
O-]mebTvw
//线程睡眠 %R#L
public static void sleep(int nSecond) e:E0"<
{ 'oNO-)p\#!
try{ DBLk!~IF
Thread.sleep(nSecond); 8bK|:B#6,
} _$NIp `d
catch(Exception e) q>f<u&
{ C$Lu]pIL*
e.printStackTrace (); r0t^g9K0
} (2ur5uk+
} wHZW `
@Q&3L~K"
//日志 I +5)Jau^S
public static void log(String sMsg) )M=ioE8`h
{ I&?Qq k
System.err.println(sMsg); Xdi:1wW@p
} B!{d-gb
~ *:F{
7g=2Z[o
public static void log(int sMsg) k$5 s{q
{ f:*vr['d
System.err.println(sMsg); G)#$]diNuX
} 1"8yLvtn
} :(dHY
a8u9aEB
J]W5[)L
/* <9ig?{'
**TestMethod.java CO-_ea U(
*/ GWsE;
package NetFox; rqv))Zo`
{l_{T4xToB
NW~z&8L
public class TestMethod { c,so`I3rI
u$%t)2+$4
U<XSj#&8|
public TestMethod() *vgl*k?)
{ ///xx/weblogic60b2_win.exe R(.}C)q3
try{ +[\eFj|=
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); ,h|qi[7
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); f~E*Zz`;
SiteFileFetch fileFetch = new SiteFileFetch(bean); Vc^HVyAx@n
fileFetch.start(); _0+0#! J!
} 6s,uXn
catch(Exception e){e.printStackTrace ();} ^@P1 JNe
I8oo~2Qw
a`Gx=8
} AV 8n(
"G>3QL+O|
>+. (r]
public static void main(String[] args) [{4MR%--
{ T0)4v-EO
new TestMethod(); js1!9%BV
} y"]n:M:(
} y(R? ,wa=]
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