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)); lVFX@I=pI
} `8-aHPF-
for(int i=0;i<nEndPos.length-1;i++) y"hM6JI
{ J'EK5=H
nEndPos = nStartPos[i+1]; xo%iL
} 0 mQ3P.9
nEndPos[nEndPos.length-1] = nFileLength; v Y\O=TZT
} KH7]`CU
} w(U/(C7R
qh'BrYu*
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//启动子线程 5 QeGx3'
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; IX(yajc[~M
for(int i=0;i<nStartPos.length;i++) >SJ$41"E
{ GW#kaqC1
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), Fs|;>Up0
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), 85fDuJ9$Z"
nStartPos,nEndPos,i); z|<oxF.
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); EVL;"
fileSplitterFetch.start(); ]aRD6F:L
} "{k )nr+7U
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), TxvPfU?
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); @e,Zmx
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", xdM#>z`;
nEndPos = " + nFileLength); IpJv\zH7
// fileSplitterFetch[nPos.length-1].start(); %MJ7u}
AL7O-D
`.W;ptZ6
//等待子线程结束 Zsogx}i-
//int count = 0; orHD3T%&
//是否结束while循环 |w2AB7EU
boolean breakWhile = false; 0_ \ g
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P` F'Nf2U
while(!bStop) D,j5k3< #
{ 3x0wk9lND
write_nPos(); A4FDR#
Utility.sleep(500); ~k0)+D}
breakWhile = true; :"^< aLj
B9DxV>mr\r
BDRVT Y(s
for(int i=0;i<nStartPos.length;i++) \,gZNe&Vv
{ ('-}"3
if(!fileSplitterFetch.bDownOver) g<4M!gi
{ Z{4aGp*
breakWhile = false; SWsv,
break; TQd FC\@f"
} B9Q.s
} Ju7C?)x
if(breakWhile) h&M RQno
break; T;r];Y(b*
fsc~$^.~\
wV&f|JO0+
//count++; ;T{/;
//if(count>4) y6Epi|8
// siteStop(); yLO &(Mb
} wv.Ulrpx.
&9_\E{o%]
HL}~W}!j
System.err.println("文件下载结束！"); u?3NBc$~A
} Rfc&OV
catch(Exception e){e.printStackTrace ();} '#i]SU&*
} N%rL=zE
9>&tMq
4_762Gu%
//获得文件长度 .hlQ?\
public long getFileSize() t-m9n*\j1
{ nuO3UD3
int nFileLength = -1; TflS@Z7C
try{ JM-ce8U
URL url = new URL(siteInfoBean.getSSiteURL()); Ym.l@(
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); LbX6p
httpConnection.setRequestProperty("User-Agent","NetFox"); nN`Z0?
EdAR<VfleA
}\939Y
int responseCode=httpConnection.getResponseCode(); q= yZx)
if(responseCode>=400) y+";
{ 8f,'p}@!d
processErrorCode(responseCode); ('**nP
return -2; //-2 represent access is error (}FW])y
} Wz-3?EQ
(' Ko#3b
|)?aH2IL
String sHeader; CaYos;Pl
-Y8ks7
C~KWH@
for(int i=1;;i++) YQ@dl
{ =(.mf
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); >'ksXA4b
//Utility.log(in.readLine()); -4vHK!l
sHeader=httpConnection.getHeaderFieldKey(i); rv,NQZ
if(sHeader!=null) "$W|/vD+
{ ,qe]fo >
if(sHeader.equals("Content-Length")) \]U<hub
{ =XMD+
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); /lr1hW~Dbk
break; {UdcX~\~
} X;OsH
} P /c Q1
else Z6IJo%s
break; O&#S4]Y
} =mKfFeO.
} _K0izKTA.
catch(IOException e){e.printStackTrace ();} g[EM]q,
catch(Exception e){e.printStackTrace ();} k5aa>6K
YPha9M$AgU
ZDOF
Utility.log(nFileLength); C#U<k0R
0i8[=
H.YIv50E
return nFileLength; sf |oNOz
} Rwc[:6;fn
]aC':55(
L_THU4^j
//保存下载信息（文件指针位置） z(g%ue\
private void write_nPos() ~\IF9!
{ cBz!U8(
try{ .cg=
output = new DataOutputStream(new FileOutputStream(tmpFile)); wr$cK'5ZL
output.writeInt(nStartPos.length); ;cv.f>Cm
for(int i=0;i<nStartPos.length;i++) FOOQ'o[}
{ ^>N8*=y
// output.writeLong(nPos); M82.khm~jM
output.writeLong(fileSplitterFetch.nStartPos); >Z#uFt0<Pm
output.writeLong(fileSplitterFetch.nEndPos); pN\)(:"8v
} NuC-qG#
output.close(); V";mWws+?#
} J+ Jt4
catch(IOException e){e.printStackTrace ();} e>L5.~i
catch(Exception e){e.printStackTrace ();} J[e}
} 2y3?!^$
0JmFQ^g(
+7| [b
//读取保存的下载信息（文件指针位置） @%6)^]m}r
private void read_nPos() ppAmN0=G
{ ]i-P-9PA4
try{ z-n>9
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); 7~_{.f
int nCount = input.readInt(); x&at^Fp
nStartPos = new long[nCount]; 2>F\&
nEndPos = new long[nCount]; h/,R{A2mO
for(int i=0;i<nStartPos.length;i++) !Tv?%? 2l
{ nN>J*02(
nStartPos = input.readLong(); r eGm>
nEndPos = input.readLong(); b6 $,Xh
} ^#]c0
input.close(); iJFr4o/R
} ):e+dt
catch(IOException e){e.printStackTrace ();} z)}3**3'y
catch(Exception e){e.printStackTrace ();} j:7*3@f
} 59V#FWe-
}$l8d/_$[
}K2 /&kZ
private void processErrorCode(int nErrorCode) ?N:B
{ :*^:T_U
System.err.println("Error Code : " + nErrorCode); $30oc Tt{
} X4a^mw\"
Odm#wL~E
2z4<N2!M
//停止文件下载 N1%p"(
public void siteStop() z<hFK+j,'^
{ C@1CanL@3
bStop = true; +#4]o }6G
for(int i=0;i<nStartPos.length;i++) l';pP^.q
fileSplitterFetch.splitterStop(); UH[<&v
o7.e'1@
u#1%P5r&X
} GD!- qH
} Y,C=@t@_
//负责部分文件的抓取 </= CZy5w
**FileSplitterFetch.java {3LA%xO
*/ #b'N}2'p#V
package NetFox; E!zX)|Z<
k'Gw!p}
ygN>"eP
import java.io.*; s.VA!@F5
import java.net.*; )>\4ULR83
^-hErsK
/t*YDWLg
public class FileSplitterFetch extends Thread { /%!~x[BeJ>
:$?Q D
u^=`%)
String sURL; //File URL fxd0e;NAAh
long nStartPos; //File Snippet Start Position ~h! 13!
long nEndPos; //File Snippet End Position bHE7yv [
int nThreadID; //Thread's ID }x:0os
boolean bDownOver = false; //Downing is over oaK.kOo
boolean bStop = false; //Stop identical h./P\eDc
FileAccessI fileAccessI = null; //File Access interface eCWPhB6l
iCP~O
pISp*&
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException hd2'AlB
{ *nRNg.i3D
this.sURL = sURL; *)'Vvu<
this.nStartPos = nStart; v*z(@<Y
this.nEndPos = nEnd; dY!u)M;~~
nThreadID = id; NLyXBV[hV
fileAccessI = new FileAccessI(sName,nStartPos);//定位 O-#TZ
} ZSB?Y1wG
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]a?bzOr,
public void run() A_R!uRD8-
{ U%>'"
while(nStartPos < nEndPos && !bStop) ;hHi@Z9
{ booRrTS
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~Y7dH Dn
try{ |quij0_'e
URL url = new URL(sURL); ^A9M;q
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 632bN=>
httpConnection.setRequestProperty("User-Agent","NetFox"); 7 ^$;
String sProperty = "bytes="+nStartPos+"-"; D#Kuo$
httpConnection.setRequestProperty("RANGE",sProperty); z-r2!^q27
Utility.log(sProperty); |^a;77nE_^
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!yJICjXj
InputStream input = httpConnection.getInputStream(); 3<:jx~y>
//logResponseHead(httpConnection); Da.G4,vLh
)C~9E 5E
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byte[] b = new byte[1024]; O )d[8jw"
int nRead; CvDxq:x
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) `@Oa lg
{ w7TJv4_
nStartPos += fileAccessI.write(b,0,nRead); =(o']ZaaA
//if(nThreadID == 1) 2C=Q8ayvX
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); (xpn`NA
} k N7Bd}
Um`!%
&,:h)
Utility.log("Thread " + nThreadID + " is over!"); b:W-l?
bDownOver = true; vB'>[jvA|
//nPos = fileAccessI.write (b,0,nRead); >''U
} P8Qyhc
catch(Exception e){e.printStackTrace ();} vB\]u.
} @N@F,~[RR2
} 9+=gke
p@ NaD=9
fmX!6Kv
//打印回应的头信息 q5DEw&UZJ
public void logResponseHead(HttpURLConnection con) TrS8h^C
{ hX:"QXx
for(int i=1;;i++) Kn`M4O
{ <y.]ImO
String header=con.getHeaderFieldKey(i); I:98$r$
if(header!=null) ULJmSe
//responseHeaders.put(header,httpConnection.getHeaderField(header)); @(g_<@Jz
Utility.log(header+" : "+con.getHeaderField(header)); WJH\~<{mP
else Lh.b5Q|
break; "R>FqX6FB
} co8"sz0(U
} $;N*cH~
yw-8#y
E H:T
public void splitterStop() nI.x
{ ElhRF{R
bStop = true; \NZIEu)5?
} m,i,n9C->
RGKYW>$0RR
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} PXzsj.
U1_@F$mq<
bV+(b9
/* Dl(3wgA
**FileAccess.java i':ydDOOHA
*//文件访问(定位，写) e}/Lk5q!
package NetFox; Q1d'~e
import java.io.*; wI]"U2L5
h,aAw#NE*
4;n6I)&.(
public class FileAccessI implements Serializable{ >(uZtYM\j
g8qgk:}
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 X[ q+619
RandomAccessFile oSavedFile; ]H-S,lmV
long nPos; (~CLn;'
;c~cet4
_vSn`
public FileAccessI() throws IOException L^2FQti>
{ Q_* "SRz
this("",0); ku$$ 1xq
} 5^']+5_vb
t!*+8Q!e
];.pK
public FileAccessI(String sName,long nPos) throws IOException 5` Te\H
{ l^ZI* z7N
oSavedFile = new RandomAccessFile(sName,"rw"); yjfat&$
this.nPos = nPos; rSXh;\MfB4
oSavedFile.seek(nPos); =mA: ctu~v
} l @^3Exwt
y_\p=0t8
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public synchronized int write(byte[] b,int nStart,int nLen) =]:>"_jN
{ 'F>'(XWWQ
int n = -1; *`ZH` V
try{ G}&Sle]
oSavedFile.write(b,nStart,nLen); n1!?"m!
n = nLen; XsnF~)YW
} aLIBD'z
catch(IOException e) (`y*V;o4
{ =Umw$+fJr
e.printStackTrace (); ;&1V0U,fx
} !\&;h
yAoe51h?
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return n; ^]{R.(#z
} E<yW\
7o8{mp'_
(SKVuR%Jj
} v4C{<8:X
m1Y>Nj[f
'fW6 .0fXa
/* _YF%V;X
**SiteInfoBean.java 9K9DF1SOa
*/ &hRvol\J
package NetFox; Yo[;W vu
foQ#a
wE~V]bmtW
public class SiteInfoBean { E9~Ghx.
i&VsW7
]xuG&O"SBV
private String sSiteURL; //Site's URL qi_Jywd:w
private String sFilePath; //Saved File's Path #5V9oKM
private String sFileName; //Saved File's Name ]\!?qsT3}
private int nSplitter; //Count of Splited Downloading File By%=W5
gG/!,Q.Qh
Y.*y9)#S6
public SiteInfoBean() \EVBwE,
{//nSplitter的缺省值为5 6L)%T02C
//default value of nSplitter is 5 q5?# 3T=
this("","","",5); i9/aAH0
} *hw\35%P`?
>yULC|'F&~
at)~]dG
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) '#k0a,<N
{ utIX %0
sSiteURL= sURL; ,lyb!k8
sFilePath = sPath; kXf'5p1
sFileName = sName; &uO%_6J
this.nSplitter = nSpiltter; \_lod kf
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$C `;fA
} +(h\fm7*-
8?%-'z.
p>upA)W]
public String getSSiteURL() Y*UA,<-
{ nVi[
return sSiteURL; jrS[f
} ?:)]h c
={z*akn,
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public void setSSiteURL(String value) mFi&YpHu3
{ 49vcoHlf
sSiteURL = value; o|$AyS{1
} :AE&Ny4
{j7uv"|X7
]bK=FIK2
public String getSFilePath() `5C,N!d8X
{ f`;j:O
return sFilePath; {QwHc5Bf
} }yz (xH
RS^lKJ1 U
7:2WgLo
public void setSFilePath(String value) gy_>`16K
{ sNLs\4v
sFilePath = value; |g//g\dd
} |fHV2Y`:g
hUF5fZqii
tfGHea)M
public String getSFileName() EUxGAj$-
{ dzDqZQY$
return sFileName; hX=A)73(
} +Nt2 +Y:O
ekWePL;rR2
<x<"n t
public void setSFileName(String value) vuoQz\
{ "t~
sFileName = value; 5.MGaU^Z$
} Y4v|ko`l%
JW3B'_0
MpF$xzh
public int getNSplitter() G{6;>8h
{ lp(8E6
return nSplitter; LyAn&h}
} /!3@]xz*
mD^jd+
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public void setNSplitter(int nCount) 3GUZ;jdn
{ :(M(>4t
nSplitter = nCount; ;e1ku|>$
} t},/}b
} +Zaj,oEE
,}K7Dg^1
x3o]U)^
/* F;7dt@5;
**Utility.java w tiny,6
*/ NnT1X;0W
package NetFox; <gQIq{B?
j,"@?Wt7
fmb} 2h
public class Utility { 4*Hgv:0?kI
RT.D"WvT
=AEBeiz
public Utility() i;_tI#:A
{ XYZ4TeW\1
paD!Z0v&
qa0 yg8,<
} 6er-{.L=
=9fajRFTt
//线程睡眠 .ZJRO>S
public static void sleep(int nSecond) /Z@tv.f
{ Is{KN!Hw
try{ 9*{[buZX
Thread.sleep(nSecond); 'U\<IL#U
} b"#WxgaF
catch(Exception e) \l]DQaOEe
{ Dk(1}%0U/
e.printStackTrace (); 'gTbA?+@5
} <7j87
} S|]X'f
Te<}*qvD
//日志 3G`aHTWk
public static void log(String sMsg) ]Zyur`
{ tm#nUw
System.err.println(sMsg); \4-"L>
} + EGD.S{
eFL=G%
}l],.J\BGX
public static void log(int sMsg) {:]9Q Tq
{ 7 D^gMN%p
System.err.println(sMsg); }L#_\
} "6us#T
} %Ntcvp)
Y[$!`);Ye
|>tKq;/
/* 83Q4On
**TestMethod.java RkBb$q9F]
*/ :QB<?HaS'
package NetFox; fM^qQM[lG
49dd5ddr
b{]z wpf
public class TestMethod { H=Y{rq@
lJis~JLd`
_PlKhv}
public TestMethod() Ft;^g3N
{ ///xx/weblogic60b2_win.exe L&%s[
try{ O^^C;U@U<1
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); ]A<~XIu
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); +(1zH-^.
SiteFileFetch fileFetch = new SiteFileFetch(bean); !`M|C?b
fileFetch.start(); 8=Z9T<K
} _q{c##Kf
catch(Exception e){e.printStackTrace ();} <\pfIJr$
N,;5{y1;J
HFaj-~b
} kAC&S!n
H s"HID
B9H@e#[
public static void main(String[] args) KNLfp1!
{ JAX*hGhkh
new TestMethod(); 9)gC6IiW
} OC<5E121>Y
} KjE+QUa
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