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)); yFqB2(Dv
} &FzZpH
for(int i=0;i<nEndPos.length-1;i++) IsiCHtY9
{ xCiq;FFR
nEndPos = nStartPos[i+1]; .\ces2,
} }W* q
nEndPos[nEndPos.length-1] = nFileLength; $~.'Tnk)
} }Ias7d?re
} [[0u|`T/
g)~"-uQQ
64-;| k4F
//启动子线程 |"EQyV
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; Ut^ {4_EC
for(int i=0;i<nStartPos.length;i++) ],ISWb
{ 4Q(GX.5
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), r5aOQ
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), Sy`7})[
nStartPos,nEndPos,i); !@kwHJkv
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); Tf?|*P
fileSplitterFetch.start(); *5|q_K Pt
} 7^Q4?(A
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), EAXbbcV
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); s:\FlQ0
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", OB5`a,5dI
nEndPos = " + nFileLength); 7gcJ.,Z.
// fileSplitterFetch[nPos.length-1].start(); W~FM^xR?p
<C,lHt
&ywU^hBh
//等待子线程结束 h#rziZ(
//int count = 0; u'+;/8
//是否结束while循环 e2l!L*[g
boolean breakWhile = false; K_sHZ
=Hwlo!
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while(!bStop) a"&Gs/QKSC
{ (7_}UT@w-
write_nPos(); +:?"P<'
Utility.sleep(500); a8laPN
breakWhile = true; '6zD`Q
YZ0Jei8+-
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for(int i=0;i<nStartPos.length;i++) ' (1`iQ;
{ B78e*nNS#2
if(!fileSplitterFetch.bDownOver) RO+N>Wkt
{ Y(3X5v?[
breakWhile = false; TcM;6h`
break; I c 2R\}q
} . +
} )UgLs|G~
if(breakWhile) !m<v@SmL\
break; 6_wj,7
{N2MskK
`}Z`aK
//count++; 7)#8p@Q
//if(count>4) 5.3=2/
// siteStop(); #%$U-ti
} BL^\"Xh$|
+<1MY'>y
nqMXE82
System.err.println("文件下载结束！"); 6z keWR
} -L&%,%
catch(Exception e){e.printStackTrace ();} U8gf_R'
} ev"f@y9Do
p.|NZXk%%a
9O2??N7f
//获得文件长度 Cl>{vSN
public long getFileSize() $WS?/H0C
{ g/f^|:
int nFileLength = -1; v%$c_'d
try{ bc}BQ|Q
URL url = new URL(siteInfoBean.getSSiteURL()); 8%EauwAx
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); *'ffMnSZ
httpConnection.setRequestProperty("User-Agent","NetFox"); V|W[>/
d$T856
?)V?6"fFP
int responseCode=httpConnection.getResponseCode(); DO{Lj#@
if(responseCode>=400) VkJBqRzBOa
{ ')#!M\1,HQ
processErrorCode(responseCode); ~,O&A B
return -2; //-2 represent access is error =jIP29+
} eWWtMnq
O@-|_N*;K
o<8SiVC2
String sHeader; *)u%KYGr
=Hf`yH\#
\;bDDTM
for(int i=1;;i++) G'IRqO*]
{ Nm4 h
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); ;*[oi
//Utility.log(in.readLine()); tx_h1[qi
sHeader=httpConnection.getHeaderFieldKey(i); M>g%wg7Ah
if(sHeader!=null) eB2a1<S&@
{ ZXH{9hxd
if(sHeader.equals("Content-Length")) 1}ER+;If
{ `*-rz<G
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); 7+;CA+;
break; h6~H5X
} -a\[`JHi
} =+ALh-
else Ce`#J6lT
break; q)Qg'l^f
} !>,XK!)
} y^[?F>wB
catch(IOException e){e.printStackTrace ();} X]+z:!
catch(Exception e){e.printStackTrace ();} =";G&)H-
k.<OO
/ht-]Js$G
Utility.log(nFileLength); >eM>Y@8=
R?5v//[
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return nFileLength; |{V@t1`
} %@'[g]hk
,.]1N:
IrMxdF~c
//保存下载信息（文件指针位置） n@_aTY
private void write_nPos() QA=mD^A
{ n7VQi+i'
try{ ' o(7@
output = new DataOutputStream(new FileOutputStream(tmpFile)); Gy6PS{yY6t
output.writeInt(nStartPos.length); sg%Ptp
for(int i=0;i<nStartPos.length;i++) AR3v,eOs
{ fjh,e
// output.writeLong(nPos); [ ~:wS@%
output.writeLong(fileSplitterFetch.nStartPos); ,~*pPhQ8m
output.writeLong(fileSplitterFetch.nEndPos); 0x,NMS
} ~djHtd>
output.close(); N}CeQ'l[R
} h[>Puoz
catch(IOException e){e.printStackTrace ();} s6(bTO.
catch(Exception e){e.printStackTrace ();} ]=vRjw
} ;!pSYcT,
RN"Ur'+
cm17hPe`}n
//读取保存的下载信息（文件指针位置） ,d@FO|G#pt
private void read_nPos() |32uC3?o
{ +j(7.6ia
try{ g27)$0&0
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); Wxa</n8S[n
int nCount = input.readInt(); H:]'r5sw
nStartPos = new long[nCount]; w=kW~gg
nEndPos = new long[nCount]; $ #bWh
for(int i=0;i<nStartPos.length;i++) :wY(</H
{ `=P=i>,
nStartPos = input.readLong(); 89P'WFOFK
nEndPos = input.readLong(); M,dp;
} :0'vzM
input.close(); D9%t67s
} 3XcFBFE
catch(IOException e){e.printStackTrace ();} )7 M
catch(Exception e){e.printStackTrace ();} R 6 -RH7.
} tvcM< e20
e/R$Sfj]
@cB6,iUr
private void processErrorCode(int nErrorCode) E_-g<Cw
{ Xq%ijo
System.err.println("Error Code : " + nErrorCode); #'8'5b
} +wGFJLHJ
Y3g<%6
;4k/h/o1#
//停止文件下载 J[al4e^
public void siteStop() >D_!d@Z
{ @*=eqO
bStop = true; k-I U}|Xz
for(int i=0;i<nStartPos.length;i++) =)f5JwZPG
fileSplitterFetch.splitterStop(); `{H!V~42
7Cx-yv
p%-;hL!
} t#2szr+
} TJUYd9O4[
//负责部分文件的抓取 ?0?+~0sI
**FileSplitterFetch.java bKQ_{cR
*/ r#B{j$Rw
package NetFox; #{5h6IC
(l}nwyh5
iQvqifDmh
import java.io.*; WO=P~F<
import java.net.*; +pxtar
LF ;gdF%@
!SThK8j$7
public class FileSplitterFetch extends Thread { H8h,JBg5<F
eA-$TSWh
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String sURL; //File URL Q|7;Zsd:
long nStartPos; //File Snippet Start Position ZJV;&[$[
long nEndPos; //File Snippet End Position &W%fsy<
int nThreadID; //Thread's ID &H/3@A3
boolean bDownOver = false; //Downing is over @5{h+^
boolean bStop = false; //Stop identical E&0]s
FileAccessI fileAccessI = null; //File Access interface Q&vU|y
:oytJhxU
&{S@v9~IT
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException C,$7fW{?
{ S7B?[SPrN[
this.sURL = sURL; {cmV{ 4Yx
this.nStartPos = nStart; qU^`fIa
this.nEndPos = nEnd; ;RS^^vDm
nThreadID = id; 8*EqG5OP
fileAccessI = new FileAccessI(sName,nStartPos);//定位 1 }_"2
} u(~(+1W
4YA1~7R
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public void run() CJt(c,!z
{ xpWY4Q
while(nStartPos < nEndPos && !bStop) gFnJDR
{ i}~U/.P
sM@1Qyv&0
41c4Xj?'
try{ 7o9[cq w
URL url = new URL(sURL); HJ!P]X_J1
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 1WAps#b.
httpConnection.setRequestProperty("User-Agent","NetFox"); B1va]=([)W
String sProperty = "bytes="+nStartPos+"-"; w%~Mg3|
httpConnection.setRequestProperty("RANGE",sProperty); +m1*ou'K
Utility.log(sProperty); n8o(>?Kw
4#ZZwa]y
B1o*phM g
InputStream input = httpConnection.getInputStream(); V BjA$.
//logResponseHead(httpConnection); oA4<AJ2
5 &s<&h
5)i+x-
byte[] b = new byte[1024]; dQI6.$?
int nRead; `FmRoMW9+
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) nQd~i0`vB
{ lGX8kAv?
nStartPos += fileAccessI.write(b,0,nRead); 6o~CX
//if(nThreadID == 1) {$'oKJy*
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); -qpe;=g&f
} uwu`ms7z 2
+,J!xy+~,
Oox,4&
Utility.log("Thread " + nThreadID + " is over!"); URMxCL^"
bDownOver = true; kI,O9z7A7
//nPos = fileAccessI.write (b,0,nRead); Y"E*#1/
} -o YJ&r
catch(Exception e){e.printStackTrace ();} Qo+Y
} @Wd1+Yky
} vzZ"TSP
?A~a}bFZ
._(5; PB"
//打印回应的头信息 NQ,2pM<*-
public void logResponseHead(HttpURLConnection con) R?}<CjI
{ >H,PST
for(int i=1;;i++) '|nAGkA
{ a@N 1"O
String header=con.getHeaderFieldKey(i); VX e7b
if(header!=null) 0yL%Pjn6
//responseHeaders.put(header,httpConnection.getHeaderField(header)); 7 '{wl,u
Utility.log(header+" : "+con.getHeaderField(header)); Env_??xq
else 8:jakOeT
break; WP4"$W
} d*Kg_He-
} J;Eg"8x]
:jGgX>GG
VevDW }4q*
public void splitterStop() c)zwyBz
{ k9iB-=X?4s
bStop = true; `,)%<}
} @!%HEs!# #
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YBQ{/"v%|
} ]Yt,|CPe2
K"VRHIhfg
N683!wNX
/* !p(N DQm
**FileAccess.java AP(%m';
*//文件访问(定位，写) S0tPnwco[~
package NetFox; z:JJ>mxV
import java.io.*; !k8j8v&
)%~<EJ*&Z
8J8@0
public class FileAccessI implements Serializable{ 7aeyddpM
>e QFY^d5
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 rY]QTS">o
RandomAccessFile oSavedFile; %Su,
long nPos; $'Qv {
"i;"
z460a[Wl
public FileAccessI() throws IOException FuFA/R=x/
{ ![{0Yw D
this("",0); 4!DXj0^
} U].3vju`c
fi';Mb3B3
+%LR1+/%b
public FileAccessI(String sName,long nPos) throws IOException '"J``=
{ YCo qe,5
oSavedFile = new RandomAccessFile(sName,"rw"); i3o;G"IcD
this.nPos = nPos; 0Y9fK? (
oSavedFile.seek(nPos); E>k!d'+tb
} Mt%=z9OLq9
NnqAr ,
w*B4>FYg
public synchronized int write(byte[] b,int nStart,int nLen) aX|LEZ;D>
{ &HJ'//bv
int n = -1; +X!QH/ 8
try{ mI-9=6T_
oSavedFile.write(b,nStart,nLen); K1m'20U
n = nLen; [M&.'X
} 0i/!nke.
catch(IOException e) 4pZ=CB+j
{ s?_H<u
e.printStackTrace (); lW3wmSWn%
} qt4^e7o
7r wNjY#
xaW9Sj0ZM
return n; _/cL"Wf
} ]$i~;f 8I
)1o<}7
yf2$HF
} A!^gF~5
|!"qz$8fB
~=Q Tv8
/* b]@@x;v$@
**SiteInfoBean.java =JfSg'7
*/ q,*([yX
package NetFox; 'uU{.bq
s[#ww =T\
d^ZrI\AJ
public class SiteInfoBean { ?$Ii_.
+z?SKc
]c\d][R N
private String sSiteURL; //Site's URL pDM95.6
private String sFilePath; //Saved File's Path vDcYz,
private String sFileName; //Saved File's Name d{:0R9
private int nSplitter; //Count of Splited Downloading File ^=7XA894
-9~WtTaV.H
ZCz#B2Sf8
public SiteInfoBean() eGQ-Ht,N
{//nSplitter的缺省值为5 _68{ {.
//default value of nSplitter is 5 zHk7!|%Y
this("","","",5); QBL|n+
} L1YiXJ,T,
<U~at+M
j/uu&\e
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) Pj{Y
{ B8.uzX'p
sSiteURL= sURL; ,@0D_&JAl
sFilePath = sPath; <_~e/+_.
sFileName = sName; 5:|=/X%#qp
this.nSplitter = nSpiltter; 0*XCAnJ^_
C5x*t Q|
^F:Bj&0v[
} -&JQdrs
i16kPU
9N V.<&~
public String getSSiteURL() MeW?z|x`'
{ QZv}\C-c
return sSiteURL; .T\_4C
} /nB|Fo_&Q
B\Uocn
3V%ts7:a
public void setSSiteURL(String value) }0idFotck
{ ]3]=RuQK2
sSiteURL = value; MZ"|Jn
} Ri;_ 8v[H|
"WZ|
M<'He.n
public String getSFilePath() IA680^
{ t$g@+1p4
return sFilePath; Nx=rw h
} yZkS
LsO}a;t5
6|Xe ],u
public void setSFilePath(String value) 4Be\5Byr
{ +0g L!r
sFilePath = value; }No8to
} r$W%d[pB
AL;4-(KH
\gR%PN
public String getSFileName() }56WAP}Z 4
{ T,h9xl9i
return sFileName; n}/4em?
} d r$E:kr
' r/xBj[Z
W_lXY Z<
public void setSFileName(String value) Y&-% N
{ "/Pq/\,R|
sFileName = value; 1P?|.W_^1
} Q)=LbR{#
v?_L_{x;W
Oi<yT"7
public int getNSplitter() ]94`7@
{ oL@K{dk
return nSplitter; !RSJb
} p0hE`!
Lg{M<Q)4
BhhFij4
public void setNSplitter(int nCount) >:HmIW0PLe
{ 1>Q4&1Vn
nSplitter = nCount; rFaG-R
} \/ipYc
} )Z)Gb~G
["[v
*/2nh%>$
/* a|#TnSk
**Utility.java _@W1?;yD
*/ %j.n^7i]^:
package NetFox; <~P!yLr
>wb Uxl%{5
[iZH[7&j
public class Utility { EjMVlZC>
~r~YR=
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public Utility() `aTw!QBfG
{ Tl2(%qB
w!'y,yb%
,3N>`]Km'
} b~r:<:;
`QtkC>[
//线程睡眠 c0Pj})-
public static void sleep(int nSecond) hQ'W7EF
{ Jy\0y[f*
try{ ;wkMa;%`g|
Thread.sleep(nSecond); .>z1BP:(
} "=1gA~T
catch(Exception e) D|ra ;d
{ 9p{n7.
e.printStackTrace (); iD*Hh-
} U8J9 #+:
} at4JLbk
*@p"
//日志 ~(8fUob
public static void log(String sMsg) 4.^T~n G
{ KJ:z\N8eo
System.err.println(sMsg); (Gw*xsn1
} ;!G#Y Oe
M[~{!0Uz g
_VVq&t}
public static void log(int sMsg) DP0@x+`k
{ @HPr;m!
System.err.println(sMsg); 5:jme$BI
} T0Xm}i
} I;-Y2*
@6|<c
BGxwPJd
/* *hru);OJr
**TestMethod.java -fXQ62:S
*/ n~]"sTC}&
package NetFox; wU>Fz*
ge(,>xB
>$TvCw
public class TestMethod { 2]Il:>n,
<D3mt Q
1Acs0`3
public TestMethod() _dRB=bl"O
{ ///xx/weblogic60b2_win.exe ?&-1(&
try{ i@.Tv.NZ
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); ,dR.Sacv
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); 0FtwDM))
SiteFileFetch fileFetch = new SiteFileFetch(bean); a#"orc j
fileFetch.start(); A&)2m
} |=*)a2
catch(Exception e){e.printStackTrace ();} bXvO+I<
eG1V:%3
Er%&y
} [K$5Rm5
X=KW >
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public static void main(String[] args) ^h$*7u"^y
{ &>C+5`bg
new TestMethod(); :`zO%h
} \Q(a`6U
} RSh_~qMX
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