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)); b-,]A2.
} zZ<ns+h
for(int i=0;i<nEndPos.length-1;i++) D l4d'&!
{ 0P3j+? N%
nEndPos = nStartPos[i+1]; -??!@R7V
} b1eK(F
nEndPos[nEndPos.length-1] = nFileLength; ^!$} BY
} p6B .s_G4
} #?L(#a$k
(QA-"9v#i,
.jLMl*6%:
//启动子线程 &S9f#Ui
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; 0zlM.rjEZ
for(int i=0;i<nStartPos.length;i++) r.Y*{!t
{ T$#FAEz
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), iLjuE)6-$
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), d3\OHkM0^
nStartPos,nEndPos,i); 9k(*?!\;
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); rSM$E
fileSplitterFetch.start(); kQqBHA
} U)SM),bE[
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), *4r s
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); 9k714bnMLX
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", 03PN{<
nEndPos = " + nFileLength); ?"5~Wwp.T
// fileSplitterFetch[nPos.length-1].start(); 8=lHUn9l
" whO}
Wg}B@:`T
//等待子线程结束 =}B4I
//int count = 0; P@^z:RS*{
//是否结束while循环 7Qm;g-)f
boolean breakWhile = false; ~ >&I^4
E.?E~}z
\f8P`oET~
while(!bStop) SJ1w1^#Pz
{ #a|6Q 8
write_nPos(); ~E^yM=:h
Utility.sleep(500); ckH$E%j
breakWhile = true; KK&<Vw|O\
))%@@l[
*#9VC)Q
for(int i=0;i<nStartPos.length;i++) T#MA#H2
{ g;u<[>'I
if(!fileSplitterFetch.bDownOver) Sb@{f<3E
{ j AJ/
breakWhile = false; {bAWc.
break; NB|RZf9M
} 0A) Vtj$
} Yio>ft&g]
if(breakWhile) xI/{)I1f
break; zbF:R[)
^yEj]]6
$|`t9-EA/
//count++; lWu9/r 1
//if(count>4) [dSDg2]
// siteStop(); [4K9|/J
} <3i4NXnL2
I_"Hgx<
oTplxF1
System.err.println("文件下载结束！"); ~8KF<2c
} i6!T`Kau
catch(Exception e){e.printStackTrace ();} aTL8l.c2
} b0~H>cnA
Gvt;Q,hH
v!pj v%
//获得文件长度 l|R<F;|
public long getFileSize() N$=(1`zM=
{ :Y}Y&mA4
int nFileLength = -1; dy2_@/T7
try{ I,CAFq
URL url = new URL(siteInfoBean.getSSiteURL()); AF9[2AH=Y
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); UX-_{I QW
httpConnection.setRequestProperty("User-Agent","NetFox"); VuX>
pJ2:` f<;
Z1)jRE2dl
int responseCode=httpConnection.getResponseCode(); v&[X&Hu[
if(responseCode>=400) F#!@}K8
{ =|qt!gY)Y
processErrorCode(responseCode); XEvGhy#
return -2; //-2 represent access is error <WQ<<s@#pb
} avHD'zU}N
2yEO=SN,(
7\\~xSXh
String sHeader; ex@,F,u>o
h a,=LV
yL.PGF1(
for(int i=1;;i++) 5vUz
{ |1<]o;:
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); xzMeKC`
//Utility.log(in.readLine()); D^N#E>,
sHeader=httpConnection.getHeaderFieldKey(i); BST7y4R)BS
if(sHeader!=null) Q}=W>|aE.
{ +qh< Fj>
if(sHeader.equals("Content-Length")) !BvTJ-e)F
{ ,E/Y@sajn+
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); r{/ G\
break; LEn=dU
} O$<%z[
} aUIc=Z
else #TW>'lF
break; <y\ Z#z
} Y?&DEKFbD
} +s/N@]5nW
catch(IOException e){e.printStackTrace ();} sw=JUfAhy
catch(Exception e){e.printStackTrace ();} s>*Q
c5wkzY h
3gV&`>@
Utility.log(nFileLength); ATMogxh
23(E3:.
|;U}'|6
return nFileLength; #^4>U&?
} MW",r;l<aM
#2lvfR|
fbzKO^Ub
//保存下载信息（文件指针位置） UpszCY4
private void write_nPos() R+kZLOE
{ j J`Zz
try{ .5KC'?
output = new DataOutputStream(new FileOutputStream(tmpFile)); xM'S ;Sg
output.writeInt(nStartPos.length); N?2#YTjR
for(int i=0;i<nStartPos.length;i++) evg7d
{ 4U! .UNi
// output.writeLong(nPos); "z#?OV5
output.writeLong(fileSplitterFetch.nStartPos); cyHaku+
output.writeLong(fileSplitterFetch.nEndPos); WFeMr%Zqh>
} ].<sAmL^
output.close(); #<tWYE
} jL7MmR#y5"
catch(IOException e){e.printStackTrace ();} S$lmEJ_
catch(Exception e){e.printStackTrace ();} <igx[2X
} fw:^Lyn9$
\@}$Wjsl
O)RzNfI^`N
//读取保存的下载信息（文件指针位置） JV?RgFy
private void read_nPos() @aiLGwh
{ F~Z0
try{ [K)1!KK,L
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); R26tQbwE
int nCount = input.readInt(); "$V8y
nStartPos = new long[nCount]; &x0TnW"g
nEndPos = new long[nCount]; x@ s`;qz
for(int i=0;i<nStartPos.length;i++) n6!Ihip$
{ ssr)f8R#,#
nStartPos = input.readLong(); CI~;B
nEndPos = input.readLong(); SJ~I r#
} =@Nv:1:r
input.close(); ^;k _
} l5y#i7q
catch(IOException e){e.printStackTrace ();} J?Ep Nie
catch(Exception e){e.printStackTrace ();} MVeQ5c(
} J6["j
jC Kt;lj
q*y9/HnI
private void processErrorCode(int nErrorCode) i[t=@^|
{ @+CSY-g$
System.err.println("Error Code : " + nErrorCode); kO3k|6f=
} " ;R3260
PRk%C0`
^; V>}08
//停止文件下载 4h_4jqf=pU
public void siteStop() CF}Nom)
{ +}-W.H%`0
bStop = true; 76i rb!-
for(int i=0;i<nStartPos.length;i++) JbC\l
fileSplitterFetch.splitterStop(); BWi 7v
wM4g1H%s
\]`(xxt1
} Tx!m6B`Y
} +|"n4iZ!)
//负责部分文件的抓取 DN8pJa
**FileSplitterFetch.java &!YH"{b
*/ qnfRN'
package NetFox; A%m`LKV~@
J,=E5T}U^
hTtp-e`
import java.io.*; W];6u
import java.net.*; !VJa$>,
x"wM_hl5L
\lbiz4^>
public class FileSplitterFetch extends Thread { \IZ4(Z
(z1%lZ}(
vYt:}$AE
String sURL; //File URL 9c;lTl^4;
long nStartPos; //File Snippet Start Position {5tEsv
long nEndPos; //File Snippet End Position / ?[gB:s
int nThreadID; //Thread's ID wCTR-pL^
boolean bDownOver = false; //Downing is over iBiA0 W
boolean bStop = false; //Stop identical 5B.??;xtaV
FileAccessI fileAccessI = null; //File Access interface W7[S7kd
$9_.Q/9>
$}UJs <-F
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException ihBl",l&Hq
{ <:{[Zvl'k
this.sURL = sURL; ?a0}^:6
this.nStartPos = nStart; +e]b,9.sR
this.nEndPos = nEnd; 8}#Lo9:,d
nThreadID = id; ylxfh(
fileAccessI = new FileAccessI(sName,nStartPos);//定位 }.$B1%2
} Lr\ B
o>A%}YU
!g&B)0u]*
public void run() Y&Lk4
{ >)A
while(nStartPos < nEndPos && !bStop) !6/IKh`J
{ t02"v4_i
l`%} {3r9
gcCYXPZp
try{ 6dy4{i
URL url = new URL(sURL); )B&<Bk+
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); ~\}EROb<
httpConnection.setRequestProperty("User-Agent","NetFox"); Q fyERa\rb
String sProperty = "bytes="+nStartPos+"-"; c3!|h1h/v
httpConnection.setRequestProperty("RANGE",sProperty); ^$,kTU'=
Utility.log(sProperty); SyVbCj
LLHOWD C(2
;)]zv\fC
InputStream input = httpConnection.getInputStream(); 4qz{D"M
//logResponseHead(httpConnection); .z>." `
WAa1H60VkS
w@ylRq
byte[] b = new byte[1024]; kJeOlO[
int nRead; U1|4vd9
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) c^WBB$v
{ %=<NqINM[
nStartPos += fileAccessI.write(b,0,nRead); ?jm2|:
//if(nThreadID == 1) tWOze, N
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); U?ic$J]N
} D&m"~wI
>(ww6vk2
+}0*_VW
Utility.log("Thread " + nThreadID + " is over!"); eC`f8=V
bDownOver = true; 446hrzW>@
//nPos = fileAccessI.write (b,0,nRead); 8=o(nFJw
} +2o|#`)i
catch(Exception e){e.printStackTrace ();} h>%JG'DV
} # %y{mn
} 2b,TkG8K
@Be:+01z
.*f4e3
//打印回应的头信息 L0VR(
public void logResponseHead(HttpURLConnection con) ?HyioLO
{ e CUcE(
for(int i=1;;i++) ZWW8Hr
{ $K5s)!
String header=con.getHeaderFieldKey(i); i@^`~vj
if(header!=null) <0 idG
//responseHeaders.put(header,httpConnection.getHeaderField(header)); oNsx Fi:
Utility.log(header+" : "+con.getHeaderField(header)); PW<wjf,rQ
else j2qfEvU
break; .u;TeP
} P]x+Q
} hGXDu;{
*AQbXw]w
P1>X5:
public void splitterStop() 8Xzx;-&4
{ y"-{6{3
bStop = true; 7[1 R}G V
} ,T~5iLKY
i4r~eneP
^JDV4>S\
} SW'KYzn
<d`UifqD
1O7ss_E
/* #R~NR8(z
**FileAccess.java k$_]b0D{4
*//文件访问(定位，写) Z|dZc wo
package NetFox; WA5kX SdIb
import java.io.*; esFL<T
&.4_4"l(
km^+ mK
public class FileAccessI implements Serializable{ =~m"TQv
-XG$ 0
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 h5keYBA
RandomAccessFile oSavedFile; 9d}nyJ
long nPos; r8>?-P
'="){
@}!$NI8
public FileAccessI() throws IOException w>Sz^_ h
{ ( +hI
this("",0); 8N_rJ)f
} cGp 6yf
"a{f? .X.
becQ5w/~
public FileAccessI(String sName,long nPos) throws IOException Cjk AQ(9
{ M=`Se&-M
oSavedFile = new RandomAccessFile(sName,"rw"); O;?~#E<6w
this.nPos = nPos; Bcon4
oSavedFile.seek(nPos); I>Yp=R
} 6l7a9IJ
bLF0MVLM
v[3sg2.
public synchronized int write(byte[] b,int nStart,int nLen) ^v|!(h\ZC
{ Hv*O9!cC
int n = -1; 'Pu;]sC
try{ C$gLi8|m
oSavedFile.write(b,nStart,nLen); GTNTx5H
n = nLen; OR8o%AxL7
} M?u)H&kEl
catch(IOException e) Sxu v}y\
{ AR3=G>hO,
e.printStackTrace (); L"/ato
} D9C; JD
CnYX\^Ow
rWqA)j*!
return n; m/nn}+*C
} $?{zV$r1
I GtH<0Du
9ksrr{tW
} lM,:c.R
x&Rp m<4
N&.p\T&t
/* TaT&x_v^~a
**SiteInfoBean.java nCB3d[/B
*/ *?fBmq[j
package NetFox; 1<|I[EI
P[i/o#
ix`xdVj`
public class SiteInfoBean { nHjwT5Q+Q
gMn)<u>
jQ}|]pj+
private String sSiteURL; //Site's URL sTyGi1
private String sFilePath; //Saved File's Path /^G+vhlf\
private String sFileName; //Saved File's Name $7YLU{0
private int nSplitter; //Count of Splited Downloading File _Y {g5t
rID]!7~
gHshG;z*
public SiteInfoBean() {Aw3Itef
{//nSplitter的缺省值为5 E5Jk+6EcMa
//default value of nSplitter is 5 32D/%dHC
this("","","",5); /p"R}&z
} r |/9Dn%
r+u\jZ
h zE)>f
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) (5&"Y?#o,
{ _P1-d`b0 a
sSiteURL= sURL; j"s(?
sFilePath = sPath; 2Wtfx" .y
sFileName = sName; DlI|~
this.nSplitter = nSpiltter; #u@!O%MJ
Rby7X*.-v
PQr N";+
} iSlVe~ef
xW~@V)OH
8w'8n
public String getSSiteURL() %xz02$k
{ sNVD"M,
return sSiteURL; h+@t8Q;gGw
} \gpKQt0
! +7ve[z
HfPeR8I%i
public void setSSiteURL(String value) "RA$Twhj
{ OQvJdjST
sSiteURL = value; n0q(EQy1U
} >w2u
-bF+uCfba
* =l9gv&
public String getSFilePath() + aFjtb
{ !ZW0yCwLQ
return sFilePath; nv]64mL3
} [bXZPIz;j
>2/zL.O
mgWtjV 8
public void setSFilePath(String value) 'P#I<?vB
{ 9nE%r\H
sFilePath = value; 5hMiCod
} )j'b7)W\
&IYkeGQr
0 CS_-
public String getSFileName() {5h_$a!TaU
{ (%Rs&/vU~
return sFileName; ~fe0Ba4
} !k63`(Ti
Z#04 ]
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public void setSFileName(String value) }s[/b"%y
{ cS"6%:hQ
sFileName = value; ZHJzh\?
} aXagiz\;
x!+a,+G
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public int getNSplitter() }1wuH
{ I_rVeMw=
return nSplitter; Fz% n!d
} XEI]T~
yrX]w3kr%
Lsdu:+-
public void setNSplitter(int nCount) j>iM(8`t1
{ T5h[{J^
nSplitter = nCount; r[~$
} .B*)A.
} zl5S)/A
3^Y-P8.zdB
^8iy(
/* ITV}f#
**Utility.java hGeRM4zVZZ
*/ eu=2a>
package NetFox; xjpW<-)MLf
53QP~[F8R]
:`K;0`C+
public class Utility { DH%X+r
vKeK]
?kSs7e>
public Utility() 21qhlkdc
{ !IS,[
c LJCLKJ
'zaB5d~l
} ;b^@o,=
G r)+O
//线程睡眠 ]rS+v^@QH
public static void sleep(int nSecond) C1J'. !
{ -_3.]o/J
try{ H;6V
Thread.sleep(nSecond); sXWMXQ3
} qA30G~S
catch(Exception e) O_ cK4
{ ?=l(29tH
e.printStackTrace (); !v-(O"a
} #?9oA4Q
} Jj!T7f*-GX
T1E=<q4
//日志 - M]C-$
public static void log(String sMsg) 9SPu 4i
{ |Bid(`t.
System.err.println(sMsg); 0czy:d,M%
} PJLA^eC7>
"7g: u-
qv:WC TAn
public static void log(int sMsg) SO)??kQ{U
{ 2+enRR~
System.err.println(sMsg); h5JXKR.1]c
} ll#PCgIm
} iAN#TCwLT7
;8@A7`^
,oCr6 ]
/* F~B8XUa3
**TestMethod.java Ah,Zm4:
*/ i[<O@Rb
package NetFox; 6Z$T&Ul{
W+S>/`N
k`-L5#`
public class TestMethod { y& )z\8
=<g\B?s]
C}!|K0t?
public TestMethod() [8"nRlXH
{ ///xx/weblogic60b2_win.exe NS1[-ng
try{ ,MLPVDN*D
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); G~JQcJFj
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); z|9 ^T@)
SiteFileFetch fileFetch = new SiteFileFetch(bean); T<OLfuV
fileFetch.start(); >4Lb+]
} V{npK(
catch(Exception e){e.printStackTrace ();} 'D1@+FFU0
X#J[Nn>
eRGip2^cq+
} cX*^PSM
u^ T2
T:si?7CR
public static void main(String[] args) 0<Y)yNsV
{ +,smjg:O
new TestMethod(); ' o5,P/6
} n8?gZ` W
} "0 v]O~s
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