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)); hUEA)c
} yA';~V\V{>
for(int i=0;i<nEndPos.length-1;i++) wR"17z7[]
{ +fQJ#?N2n
nEndPos = nStartPos[i+1]; dZ4c!3'F
} Q 87'zf
nEndPos[nEndPos.length-1] = nFileLength; $<3^( y
} ,}NTV~
} -wh
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4zZ.v"laVM
//启动子线程 x~](d8*=
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; s&XL{FE
for(int i=0;i<nStartPos.length;i++) o.s(=iG
{ bRr3:"=sE
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), F45-M[z
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), I__a}|T%
nStartPos,nEndPos,i); M C y~~DL
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); PZI6{KOis
fileSplitterFetch.start(); m>*~tP
} cM]ZYi
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), m|v$F,Lv
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); 8Y:x+v5
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", }T}xVd0
nEndPos = " + nFileLength); 5=8t<v1Bn
// fileSplitterFetch[nPos.length-1].start(); R\]C;@J<
-lR7 @S
*Rxn3tR7
//等待子线程结束 Rr}m(e=
//int count = 0; gMp' S
//是否结束while循环 3rR1/\
boolean breakWhile = false; `$q0fTz
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while(!bStop) \ _?d?:#RD
{ s'bTP(wl9
write_nPos(); ,5AEtoF
Utility.sleep(500); %pqB/
breakWhile = true; Zay%QNsb
'%YE#1*gH
8s %YudW
for(int i=0;i<nStartPos.length;i++) L~RFI&b
{ c0;rvw7
if(!fileSplitterFetch.bDownOver) %/qwqo`Q
{ z[y
breakWhile = false; A4rkwM
break; u'T-}95 V
} Ys|SacWC
} ?Cx=!k.
if(breakWhile) WQbjq}RfI
break; \[]?9Z=n
OL_jU2,fv
fK2r6D9
//count++; T6."j_
//if(count>4) ) $0>L5d:
// siteStop(); mu5r4W47
} Ty#sY'%
WdB\n/BWB
Ey=}bBx
System.err.println("文件下载结束！"); >?6HUUQ
} JpxQS~VX
catch(Exception e){e.printStackTrace ();} Nr).*]g@~
} dGz4`1(>
Z]x6np
mI]gDL1
//获得文件长度 h4+*ssnYV
public long getFileSize() d24_,o\_
{ ?'tRu !~
int nFileLength = -1; >(.Y%$9"E
try{ 7|GSs=
URL url = new URL(siteInfoBean.getSSiteURL()); qw>vu7/z
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); "h|kf% W
httpConnection.setRequestProperty("User-Agent","NetFox"); \A)Pcc}7
A;dD'Kgl
ZX#60o8
int responseCode=httpConnection.getResponseCode(); 9hh~u -8L
if(responseCode>=400) n{&;@mgI
{ w'E?L`c
processErrorCode(responseCode); b=U3&CV9
return -2; //-2 represent access is error p#_5w
} GLX{EG9Z
tGzp=PyA
ayQeT
String sHeader; _O;4>
CGkx_E]
v`]y:Ku|wR
for(int i=1;;i++) >Bu9D
{ nF<xJs
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); \Hf/8!q
//Utility.log(in.readLine()); gXM+N(M-
sHeader=httpConnection.getHeaderFieldKey(i); pf%;*
if(sHeader!=null) F^`+.G\
{ Nwe-7/Q
if(sHeader.equals("Content-Length")) yqVoedN
{ *M_^I)*L
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); <q>d@Foi
break; &]shBvzl^
} (E,Ibz2G:e
} h=JW^\?\]
else >5?:iaq z
break; zqBzataR:
} \ 9iiS(e
} gNc;P[
catch(IOException e){e.printStackTrace ();} WW>m`RU`
catch(Exception e){e.printStackTrace ();} Tj{3#?]Ho
h+A+>kC5
t\TxK7i
Utility.log(nFileLength); ;NrPMz
&flRrJ
B2'TRXIm1U
return nFileLength; l2}X\N&q
} =N8_S$nx(
FOsxId[f9
YDj5+'y
//保存下载信息（文件指针位置） 08D:2 z1z
private void write_nPos() FSAX,Y
{ C"%B>e
try{ V|[NL4
output = new DataOutputStream(new FileOutputStream(tmpFile)); `@v;QLD"d<
output.writeInt(nStartPos.length); 4>a(!ht
for(int i=0;i<nStartPos.length;i++) "tK|/R+
{ %>6ilGQ+
// output.writeLong(nPos); c!'\k,ma<9
output.writeLong(fileSplitterFetch.nStartPos); &I(\:|`o
output.writeLong(fileSplitterFetch.nEndPos); qxsHhyB_n;
} BW}M/
output.close(); r4DHALu#)
} qvK/}
catch(IOException e){e.printStackTrace ();} <;O^3_'
catch(Exception e){e.printStackTrace ();} Q\T?t
} 8 H3u"
6EO@Xf7,
VX>j2Z'
//读取保存的下载信息（文件指针位置） 5Pxx)F9]
private void read_nPos() .Eb]}8/}E
{ oif|X7H;
try{ 4*Gv0#dga
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); 41s\^'^&
int nCount = input.readInt(); j"aY\cLr t
nStartPos = new long[nCount]; T93st<F=R
nEndPos = new long[nCount]; &[_@f#
for(int i=0;i<nStartPos.length;i++) C/#pK2xY
{ 'Cz*p,
nStartPos = input.readLong(); jD}h`(bE
nEndPos = input.readLong(); S'kgpF"bm
} O`"~AY&
input.close(); +!E9$U>6%
} Zq<j}vVJ
catch(IOException e){e.printStackTrace ();} 0a^bAEP
catch(Exception e){e.printStackTrace ();} |WEl5bNc3
} LME&qKe5
'bz&m(!
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private void processErrorCode(int nErrorCode) =QbOvIq
{ nE*S3
System.err.println("Error Code : " + nErrorCode); sQ,xTWdj
} lX)AbK]nb
k?TZY|_
gx',K1T
//停止文件下载 TI/RJF b
public void siteStop() bt_c$TN
{ :]]x^wony~
bStop = true; ;1{=t!z=
for(int i=0;i<nStartPos.length;i++) #;W4$q
fileSplitterFetch.splitterStop(); (GC5r#AnS
V$O6m|q
UcOP 0_/
} +,AzxP _y
} 8ih_S2Cd
//负责部分文件的抓取 D7JrGaF{
**FileSplitterFetch.java :KA)4[#;W
*/ ) \TH'
package NetFox; h6^|f%\w*i
sgGA0af
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import java.io.*; V,0$mBYa
import java.net.*; Wf"GA i
&rD8ng+$
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public class FileSplitterFetch extends Thread { /4 OmnE;
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9_iwikD
String sURL; //File URL PnInsf%;
long nStartPos; //File Snippet Start Position q5=,\S3=
long nEndPos; //File Snippet End Position =~Qg(=U0U
int nThreadID; //Thread's ID zrG
boolean bDownOver = false; //Downing is over VPuR4p.
boolean bStop = false; //Stop identical SA&(%f1d
FileAccessI fileAccessI = null; //File Access interface naH(lz|v
*<y9.\zY<
DB-79U%W
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException .5o~^
{ /|P{t{^WM
this.sURL = sURL; f!R7v|jP
this.nStartPos = nStart; %;v~MC@
this.nEndPos = nEnd; nKS*y*
nThreadID = id; "aCB}
fileAccessI = new FileAccessI(sName,nStartPos);//定位 #k|f>D4
} @6tczU}ak
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public void run() *jWh4F,
{ f$kbb6juL
while(nStartPos < nEndPos && !bStop) G'#u!<(^h
{ 8IQ}%|lN
+hr|$
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try{ Ky,upU
URL url = new URL(sURL); <I tS_/z
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); )UF'y{K}
httpConnection.setRequestProperty("User-Agent","NetFox"); u/6if9B
String sProperty = "bytes="+nStartPos+"-"; 9N)I\lcY
httpConnection.setRequestProperty("RANGE",sProperty); Qkx*T9W
Utility.log(sProperty); %_4#WI
kk6 !krZ
T$%QK?B
InputStream input = httpConnection.getInputStream(); 8>#ZU]cG
//logResponseHead(httpConnection); GdNhEv
OUF%DMl4
gj @9(dk%
byte[] b = new byte[1024]; cnQ2/ZZp~
int nRead; WPNw")t!
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) SJa>!]U'xI
{ P-gjSE|yh
nStartPos += fileAccessI.write(b,0,nRead); r(uo-/7z
//if(nThreadID == 1) oxN5:)
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); N<a%l J
} XX%K_p`&Z
u*P@Nuy6
dhLR#m30T
Utility.log("Thread " + nThreadID + " is over!"); gjN'D!'E1D
bDownOver = true; ^@RvCJ+
//nPos = fileAccessI.write (b,0,nRead); g=Xy{Vm
} UCfouQCj
catch(Exception e){e.printStackTrace ();} W}TP(~x'N
} ,3T"fT-(
} Uoe;=P@
P658 XKE
{R(CGrI
//打印回应的头信息 {cOx0=
public void logResponseHead(HttpURLConnection con) 7`t"fS
{ >| ,`E
for(int i=1;;i++) _v0iH
{ E]/2u3p
String header=con.getHeaderFieldKey(i); abUO3 Y{
if(header!=null) IJ2'
//responseHeaders.put(header,httpConnection.getHeaderField(header)); {TpbUj0
Utility.log(header+" : "+con.getHeaderField(header)); s9CmR]C
else CZu=/8?
break; BQ Vro;#Jc
} l`N#~<.
} %\sE\]K
J QnaXjW2
O{~Xp!QQt
public void splitterStop() G>0d^bx;E
{ \|QB;7u
bStop = true; z=U+FHdh/-
} W0sLMHq
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-_5Dk'R#`
} ZM-P
Gkem_Z
T%6JVFD
/* "X2'k@s`
**FileAccess.java ]goJ- &
*//文件访问(定位，写) a<\n$E#q
package NetFox; D|)_c1g
import java.io.*; lCp6UkE
06%-tAq:
jGz~}&B
public class FileAccessI implements Serializable{ l9Ol|Cb&
wods
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 /KOI%x
RandomAccessFile oSavedFile; 9M27;"gK
long nPos; YFJaf"?8g
57{T p:|
d%qi~koN_
public FileAccessI() throws IOException d}:-Q?
{ o^X3YaS)
this("",0); 9|<Li[
} ^Z9bA(w8
J+IItO4%
f<wYJGI
public FileAccessI(String sName,long nPos) throws IOException -+1O*L!
{ )SJM:E
oSavedFile = new RandomAccessFile(sName,"rw"); 3 5.&!4}
this.nPos = nPos; G-9i
oSavedFile.seek(nPos); $%DoLpE>
} )GVTa4}p
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2yn"K|
public synchronized int write(byte[] b,int nStart,int nLen) E-C]<{`O
{ L%Zr3Ct
int n = -1; K)>F03=uE
try{ K<5yjG8&
oSavedFile.write(b,nStart,nLen); X/:V{2
n = nLen; vLN KX;9
} rD <T
catch(IOException e) OeASB}
{ Oo;]j)z
e.printStackTrace (); X\Zan$oi
} K\%\p$ZD
4y3c=L No
v"yu7tZ3N
return n; B2]52Fg-"
} V{oFig 6
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uoE+:,P
} )r{Wj*u
iZfZF
Sdmz(R
/* PjBAf'
**SiteInfoBean.java ,v})
*/ q&>fKSnKs
package NetFox; 1O0. CC,p
G) KI{D
hmkb!)
public class SiteInfoBean { ZKEoU!
2! ,ndLA
9Jh&C5\\
private String sSiteURL; //Site's URL 0~BaQ, A@
private String sFilePath; //Saved File's Path h.#:7d(g
private String sFileName; //Saved File's Name 8Snv, Lb`^
private int nSplitter; //Count of Splited Downloading File A+Isk{d
td%J.&K_*'
Pd&KAu|<`
public SiteInfoBean() )-5eIy
{//nSplitter的缺省值为5 )-[$m%
//default value of nSplitter is 5 tKUW
this("","","",5); yW'{Z]09
} [Lje?M* r
L:Rg3eo
kJuG haO
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) CtN\-E-
{ wg)Bx#>\L:
sSiteURL= sURL; B/a`5&G]
sFilePath = sPath; )C?H m^#
sFileName = sName; ej_u):G*
this.nSplitter = nSpiltter; #KoI8U"
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AFL'Ox]0
} ]>[TF'pIAx
0'F/z%SMj
C)i8XX
public String getSSiteURL() LWqKSNE;
{ FNraof @Oy
return sSiteURL; kBA.N l7
} bi}aVtG~z
dF51_Kk
~;$QSO\2h
public void setSSiteURL(String value) L3oL>r'|
{ .yfp-n4H
sSiteURL = value; $s}w23nB
} 3AdYZ7J
<& PU%^Ha
sS{Co8EJn
public String getSFilePath() ^wZx=kas
{ TC<Rg?&yb
return sFilePath; 6c^?DLy9B
} e)?}2
hzqgsmT)
m,kYE9{
public void setSFilePath(String value) p+?`ru
{ Dom]w.W5
sFilePath = value; ,\ 1X\
} KNN{2thy `
I$sXbM;z=
0/]h"5H3
public String getSFileName() D`G;C
{ :I&y@@UG
return sFileName; RYvdfj.ij
} DRRQ]eK0
CB>W# P%
(|AZO!
public void setSFileName(String value) X(E`cH |
{ #]1jvB
sFileName = value; ENqZ=Lyq
} %pxJ27Q
rlh:|#GTJ
kw z6SObQ
public int getNSplitter() `,~'T [
{ \(Nx)F
return nSplitter; j<!dpt
} aTm R~k
ML|?H1m>
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public void setNSplitter(int nCount) AEj%8jh
{ :+\sKEzL
nSplitter = nCount; 4=^Ha%l
} ]Zh$9YK
} M __S)
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w3 vZ}1|
/* 1!)'dL0mI
**Utility.java 4KxuSI^q
*/ yy/'B:g
package NetFox; Jjj;v2uSK
Ppl :_Of
j|[$P4w}U
public class Utility { F|+B8&-v
_nz_.w0H9
,<P"\W
public Utility() yph@H!@
{ aJ=)5%$6kc
`Mg3P_}=
l v:GiA"X
} 0@{bpc rc
_VgFuU$h
//线程睡眠 X4\T=Q?uLx
public static void sleep(int nSecond) Or$"f3gq
{ ?1r;6
try{ QPp31o.!5
Thread.sleep(nSecond); ~eP~c"L
} Xsanc@w)^C
catch(Exception e) HhCFAq"j
{ b-VQn5W
e.printStackTrace (); Q~f]?a`
} @b 17jmq{
} D,p2MBr
1jKj'7/K
//日志 wpN [0^M-0
public static void log(String sMsg) zobFUFx
{ a(fiW%eFb
System.err.println(sMsg); }+`,AC`RM
} Q: -&
46 0/eW\
gGCr~.5
public static void log(int sMsg) P5G0fq7
{ Rq2bj_j
System.err.println(sMsg); h*<`ct xL
} .#tA .%
} !a V:T&6
N@Ap|`Ei
< <0[PJ
/* >\'}&oi
**TestMethod.java {%('|(57
*/ 8f~*T
package NetFox; !W&|kvT^
U74L:&yLI
9_svtO]P
public class TestMethod { ]YZ_kc^(V;
F&7Z(
vnbY^ASdw
public TestMethod() t6e6v=.Pg
{ ///xx/weblogic60b2_win.exe &'/PEOu&}G
try{ rcLF:gd]E
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); +DefV,Ny
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); $u,A/7\s
SiteFileFetch fileFetch = new SiteFileFetch(bean); B&KIM{j\
fileFetch.start(); BUi,+NdIk
} Cv>~%<
catch(Exception e){e.printStackTrace ();} h0 %M+g
#NMQN*J>D
}YC=q
} w0yzC0yBk
`;R$Ji=>
"\~>[on
public static void main(String[] args) \zA3H$Df~
{ g=v'[JPd
new TestMethod(); &,Rye Q
} 7?_gm>]a
} k&K'FaM!
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