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)); x\bRj>%(
} W8yfa[z~J
for(int i=0;i<nEndPos.length-1;i++) ;Q>3N(
{ W3V{Xk|
nEndPos = nStartPos[i+1]; LYy:IBI7_
} T3t~=b>&L
nEndPos[nEndPos.length-1] = nFileLength; Ul713Bjz
} Fma`Cm.
} mf;^b.mKh
h[|zs>p
dI ZTLb"a
//启动子线程 C3b0`|5
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; GE~(N N
for(int i=0;i<nStartPos.length;i++) E2h;hr;W
{ WQLHjGehe
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), t2-nCRXEP
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), k`7.p,;}U
nStartPos,nEndPos,i); zUEfa!#?
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 4=F]`Lql
fileSplitterFetch.start(); `\|3 ~_v
} KB,~u*~!
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), @Uj_+c q
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); t1:S!@
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", 8/>wgY
nEndPos = " + nFileLength); $>h!J.t
// fileSplitterFetch[nPos.length-1].start(); rGn5QV
%hQMC'c
kk/+Vx~
//等待子线程结束 %j[LRY/
//int count = 0; YKw!pu=
//是否结束while循环 AeY$.b
boolean breakWhile = false; %is,t<G
ny
3dX=xuQ%/
while(!bStop) @1/}-.(n
{ jgo<#AJ/E
write_nPos(); f.$aFOn
Utility.sleep(500); cJHABdK-
breakWhile = true; }*B qi7E>
KXx@ {cv
PQ&Q71
for(int i=0;i<nStartPos.length;i++) /_:T\`5uO
{ DUuC3^R
if(!fileSplitterFetch.bDownOver) {glqWFT
{ A"BtVy[[9
breakWhile = false; V6z@"+
break; v/aPiFlw
} KT lP:pB;
} *m| t=9E
if(breakWhile) ph8Jn+|E
break; |>IUtUg\
0?6If+AC
:?$Sb8OuIL
//count++; ER;lkF`RF
//if(count>4) /H%<oAjp6
// siteStop(); 3I;xU(rv
} a*W_fxb
^z*):e
5!SoN}$
System.err.println("文件下载结束！"); /Oq)3fU e
} 4Wi8$
catch(Exception e){e.printStackTrace ();} 9+'@
} M}=s3[d(,
h+B'_`(
5D]30
//获得文件长度 Fi?32e4KI5
public long getFileSize() bRK CY6
{ '&.)T2Kw
int nFileLength = -1; R8=I)I-8
try{ ?ae[dif
URL url = new URL(siteInfoBean.getSSiteURL()); 4]DAh
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); z\Pe{J
httpConnection.setRequestProperty("User-Agent","NetFox"); .# !'c
Nl$gU3kL
;o-\.=l
int responseCode=httpConnection.getResponseCode(); TbKP8zw{
if(responseCode>=400) O?nPxa<
{ H)`CncB
processErrorCode(responseCode); xfV,==uF
return -2; //-2 represent access is error xZ.~:V03\t
} W9&0k+#^
93E,
\A'|XdQ
String sHeader; [)Z'N/;0
.0nn0)"
:rz9M@7
for(int i=1;;i++) $zk^yumdE
{ wMH[QYb<*
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); u(V
//Utility.log(in.readLine()); ;Pol#0_(
sHeader=httpConnection.getHeaderFieldKey(i); Cec9#C
if(sHeader!=null) "*Lj8C3|n
{ 8iMF8\
if(sHeader.equals("Content-Length")) Vl5SL{+D
{ lv<iJH\
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); ~`*1*;Q<H|
break; ?1GY%-
} d\~p5_5.
} M!eoe5
else pP|,7c5
break; 0K=Qf69Y
} zW*}`S"
} +V)qep"
catch(IOException e){e.printStackTrace ();} ^=eq .(>
catch(Exception e){e.printStackTrace ();} 89LpklD
dO>k5!ge|:
mgi,b2
Utility.log(nFileLength); vVI6m{zYV
!UBy%DN~k
j y7
return nFileLength; |ZS 57c:
} Yta1`
7cIC&(h5
./5jx2V
//保存下载信息（文件指针位置） BX@pt;$ek7
private void write_nPos() q:vz?G
{ VLf g[*k
try{ J&A;#<qY
output = new DataOutputStream(new FileOutputStream(tmpFile)); ykxbX
output.writeInt(nStartPos.length); S3SV.C:z>
for(int i=0;i<nStartPos.length;i++) Wm<z?.lS
{ ;(K
// output.writeLong(nPos); q.-y)C) ;
output.writeLong(fileSplitterFetch.nStartPos); i\(\MzW*'
output.writeLong(fileSplitterFetch.nEndPos); ,VAp>x+O
} .2e1S{9
output.close(); /@Ez" ?V2
} >Z *iE"9"
catch(IOException e){e.printStackTrace ();} b& V`<'{
catch(Exception e){e.printStackTrace ();} yc*<:(p
} d4%dIR)
s0r"N7~
([Ebsj
//读取保存的下载信息（文件指针位置） ?8Et[tFg
private void read_nPos() wuKl-:S;Vs
{ ;P3>>DZ
try{ \@i=)dA
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); PfyRZ[3)c
int nCount = input.readInt(); fCB:733H
nStartPos = new long[nCount]; "ml?7Xl,n
nEndPos = new long[nCount]; Yj) e$f
for(int i=0;i<nStartPos.length;i++) QjLji+L
{ p"KU7-BfvC
nStartPos = input.readLong(); O:1DOUYXs
nEndPos = input.readLong(); -PM)EGSk{
} h}avX*Lx_
input.close(); #Rc5c+/(
} eK9TAW
catch(IOException e){e.printStackTrace ();} -n$ewV
catch(Exception e){e.printStackTrace ();} CD}Ns
} Raefj(^V
Tj`yJ!0
^\:yf.k
private void processErrorCode(int nErrorCode) a'uU,Eb}#w
{ 6)ycmu;!$
System.err.println("Error Code : " + nErrorCode); ?yp0$r/
} _ENuwBYW-
Yj3P 7k$c
Te;gVG*
//停止文件下载 ]c}=5m/
public void siteStop() ymtd>P"
{ :7\9xH
bStop = true; h4Ia>^@
for(int i=0;i<nStartPos.length;i++) B20_ig:
fileSplitterFetch.splitterStop(); PPa^o8jd
+e'X;
7IW> >RBF
} Y;,Hzmbs6w
} l)Zs-V!M^\
//负责部分文件的抓取 NY@"&p'Q
**FileSplitterFetch.java {]^2R>0Q
*/ `@|w>8bMz{
package NetFox; #XI"@pD
hq?jdNy :
rs:Q%V ^
import java.io.*; @rO4y`
import java.net.*; $M':&i5`,
=MC~GXJSNw
v)):$s?WB
public class FileSplitterFetch extends Thread { Wt J{
&EovZ@u
Fd7*]a
String sURL; //File URL G AQ 'Ti1!
long nStartPos; //File Snippet Start Position 8.?E[~
long nEndPos; //File Snippet End Position , H2YpZk
int nThreadID; //Thread's ID h>wcT VF
boolean bDownOver = false; //Downing is over m"Qq{p|'
boolean bStop = false; //Stop identical ^mg*;8eGa
FileAccessI fileAccessI = null; //File Access interface [T`}yb@
3sFeP&
8Mu;U3cIW
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException U<47WfcW
{ Pr+~Kif
this.sURL = sURL; C c*({
this.nStartPos = nStart; HR60
this.nEndPos = nEnd; ;LRW 8Wd
nThreadID = id; M$A#I51
fileAccessI = new FileAccessI(sName,nStartPos);//定位 &aPl`"j
} 7yI`e*EOD
dn,gZ"<
$D'^t(
public void run() WA.AFt
{ i-W
while(nStartPos < nEndPos && !bStop) '# z]M
{ RH(V^09[o
[;KmT{I9
z<pJYpxH
try{ \cQ .|S
URL url = new URL(sURL); R#(G%66
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); %y"J8;U
httpConnection.setRequestProperty("User-Agent","NetFox"); vG Vd
String sProperty = "bytes="+nStartPos+"-"; "+|L_iuNQ
httpConnection.setRequestProperty("RANGE",sProperty); s&'BM~WI
Utility.log(sProperty); !gH9ay
q* !3C
K>1X}ZMdD(
InputStream input = httpConnection.getInputStream(); @(:v_l
//logResponseHead(httpConnection); hVP IHQt
alm- r-Kb3
8$vK5Dnn8
byte[] b = new byte[1024]; `qiQ$kz
int nRead; gUVn;_
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) &Y7C0v
{ (9$"#o
nStartPos += fileAccessI.write(b,0,nRead); 0mexF@
//if(nThreadID == 1) '{f=hE_/
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); e*]r
} jtKn3m7 +p
:gI.l1
a3@w|KLt
Utility.log("Thread " + nThreadID + " is over!"); lj2=._@R
bDownOver = true; tNnyue{p
//nPos = fileAccessI.write (b,0,nRead); !e3YnlE
} Q_zr\RM>
catch(Exception e){e.printStackTrace ();} 4tXSYHd3
} 1;&;5
} =Q(vni83<
DjHp+TyT
8)xt(~qF
//打印回应的头信息 ~rv})4h
public void logResponseHead(HttpURLConnection con) $/_qE
{ SwH2$:f
for(int i=1;;i++) $h28(K%
{ Ip?]K*sq
String header=con.getHeaderFieldKey(i); 'v&}(
if(header!=null) S>Z|)I
//responseHeaders.put(header,httpConnection.getHeaderField(header)); pOga6'aB)
Utility.log(header+" : "+con.getHeaderField(header)); >UHa
else #S5`Pd!I
break; h`5)2n+P
} XU-m"_t
} nWWM2v
8`v$liH
H?yE3w
public void splitterStop() bAF )Bli
{ i0pU!`0
bStop = true; Tby,J B^U
} ~}%~oT
?m;;D'1j
RuAlB*
} A^Cj1:,
ohQAA h
4TRG.$2[
/* l@~LV}BI
**FileAccess.java 3HiFISA*
*//文件访问(定位，写) .mxTfP=9
package NetFox; xiM&$<LpR
import java.io.*; G&9#*<F$c
I&]G
M{N(~ql
public class FileAccessI implements Serializable{ 6Nh0
d^V$Z6* ]
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 E9 Y\X
RandomAccessFile oSavedFile; 9=+-QdX+0]
long nPos; WZFH@I28
1BTIJ Gw
9dKul,c
public FileAccessI() throws IOException 7#2j>G{?]v
{ >nnY:7m
this("",0); KMjg;!y
} Xm_$ dZ
smU4jh9S
$v27]"]
public FileAccessI(String sName,long nPos) throws IOException g9mG`f
{ l]#!+@
oSavedFile = new RandomAccessFile(sName,"rw"); c^.l2Q!
this.nPos = nPos; =-jD~rN4;P
oSavedFile.seek(nPos); N$alUx*
} Y=B3q8l5
fA^Em)cs2
"="O >
public synchronized int write(byte[] b,int nStart,int nLen) n:#TOU1ix<
{ F0dI/+
int n = -1; uV]ULm#,i
try{ *l>0t]5YH
oSavedFile.write(b,nStart,nLen); i~yX tya
n = nLen; $3P`DJo
} eD;6okdP
catch(IOException e) }e{qW
{ K|^wc$
e.printStackTrace (); xtfRrX^
} D`o<,Y
3y`F<&sA
f7<pEGb
return n; .v`b[4M4
} yTAvF\s$(
$H2GbZ-I
@}LZ! y
} KL3<Iz]
]]uHM}l
l";'6;g
/* L-h$Z0]_F
**SiteInfoBean.java oXYMoi
*/ 6rDfQ`f\p
package NetFox; 6Wf^0ok
zV.pol
Tz-X o
public class SiteInfoBean { cCdX0@hY
}NmNanW^
|X(2Zv^O
private String sSiteURL; //Site's URL /Jlv"R1,
private String sFilePath; //Saved File's Path eti`O
private String sFileName; //Saved File's Name 'jaoO9KY K
private int nSplitter; //Count of Splited Downloading File >|udWd^$3
T] | d5E
+]!lS7nsW
public SiteInfoBean() \2!!L=&4G
{//nSplitter的缺省值为5 ;#anZC;
//default value of nSplitter is 5 <+]f`c*Z
this("","","",5); zQ8!rCkg4
} y!Cc?$]_Y
_ Jc2&(;
hU {-a`
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) yfe'>]7
{ %%}A|,
sSiteURL= sURL; ^gR+S
sFilePath = sPath; ]qktj=p
sFileName = sName; l\Ftr_Dk
this.nSplitter = nSpiltter; Wd 2sh
:d' 5O8
gRgog*z
} 'ZHdV,dd
;st\I
u?0d[mC
public String getSSiteURL() ]> G&jd7
{ igkz2SI
return sSiteURL; o'=VZT9
} _6LoVS
-T_\f?V88
_j ;3-m
public void setSSiteURL(String value) t&RruwN_;
{ +"!aM?o
sSiteURL = value; B;t=B_oK
} E_:QSy5G
]T<^{jG
1mW%
public String getSFilePath() hu@7?f_"L/
{ 9f+RAN(
return sFilePath; 1:NS}r+>3.
} Y 62r
uHM@h{r
nWgv~{,x
public void setSFilePath(String value) 7TWNB{ K_
{ Sp?NfJ\Ie
sFilePath = value; o$J6 ~dn
} RUXCq`)"<
+x1/-J8_sg
0|Ucd
public String getSFileName() 8jnz}aBd
{ !1:@8q
return sFileName; w]!0<
} R}{GwbF_\
0i@:KYP
j6>tH"i
public void setSFileName(String value) %_f;G+fK\p
{ .9M.|
sFileName = value; U[8{_h<#
} Ijo(^v@
Yp5L+~J[
=3'(A14C=
public int getNSplitter() 6?gi_3g
{ uP|FJLY
return nSplitter; SkP[|g'56
} `deYi2z
R]L2(' B
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public void setNSplitter(int nCount) Xr_pgW|
{ +_mr
nSplitter = nCount; rla:<6tt
} G$=-,6kZO
} y-+G wa3
@$U e$
]PX}b
/* Z)9R9s
**Utility.java %e=!nRc
*/ O%JSViPw
package NetFox; t4K56H.L?
C0m\SNR
=ApY9`
public class Utility { \ TL82H@D
k0ItG?Cv
*\ECf.7jz
public Utility() 8wFn}lw&
{ P6Xp<^%E
w|Qd`
S+T|a:]\7
} Gp|JU Fo
q=0 pQ1>
//线程睡眠 =/Juh7[C
public static void sleep(int nSecond) uqZ3Hyb
{ ^gg!Me
try{ E(Gr0#8
Thread.sleep(nSecond); 3|eUy_d3
} 9g@NcJ]
catch(Exception e) -Ktwo_V*
{ Yj8&
e.printStackTrace (); <GfVMD
} qgexb\x\4
} 2d&^Sp&11
;`jU_
//日志 vm}G[
public static void log(String sMsg) 8S>>7z!U
{ {D(,ft;s^
System.err.println(sMsg); yazZw}};
} !0jq6[&
n;OHH{E{
A{`]&K1u
public static void log(int sMsg) 6>B \|
{ vttrKVA
System.err.println(sMsg); >\bPZf)tJ)
} /'&v4C^y>
} Zi1YZxF`Y
AbY;H
a4by^
/* WZ*&@|w
**TestMethod.java Sx&mv.?X
*/ :ICr\FY$
package NetFox; gb-tNhJa@b
sU%"azc
eH[y[~r
public class TestMethod { fsI`DjKi)
#W5Yw>$
/(zB0TEd
public TestMethod() D_ ug-<QT
{ ///xx/weblogic60b2_win.exe 3"tg+DncC
try{ Pd],}/ZG-
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); i'HST|!j
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); *vs~SzF$
SiteFileFetch fileFetch = new SiteFileFetch(bean); #pa\2d|
fileFetch.start(); 8S=c^_PJ
} e7|d=[kW
catch(Exception e){e.printStackTrace ();} sZm^&h;
4vGbG:x
H%T3Pc
} )"~=7)~<^
V"g~q?@F
R `Q?J[e
public static void main(String[] args) 0 r3N^_}
{ 8;.` {'r
new TestMethod(); P:a*t[+
} *NjMb{[ZQ
} Dauo(Uhuo
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