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)); JJl7JwSTW
} Q @2(aR
for(int i=0;i<nEndPos.length-1;i++) :HW>9nD.
{ wO"GtVd
nEndPos = nStartPos[i+1]; i<u9:W
} y3yvZD
nEndPos[nEndPos.length-1] = nFileLength; G[q9A$yw
} 0RyFv+
} PZ34*q
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?mOg@) wx
//启动子线程 <pOl[5v]
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; *fP(6e#G,
for(int i=0;i<nStartPos.length;i++) >QI~`MiI
{ .v,bXU$@YG
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 6s,2NeVWa
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), Z5>V{o
nStartPos,nEndPos,i); j,t~
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); e d;"bb
fileSplitterFetch.start(); L#j|2H|
} 6;JP76PD
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), ozxYH],
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); Z( #Ln
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", |mj# 0
nEndPos = " + nFileLength); +t>XxYScx
// fileSplitterFetch[nPos.length-1].start(); T_~KxQ
M5Wl3tZL
=hcPTU-QU
//等待子线程结束 UE)fUTS
//int count = 0; ~Oh=
//是否结束while循环 g+9v$[!
boolean breakWhile = false; !BRcq~-.
@*_ZoO7{
XOxB (0@
while(!bStop) ?f@ 9nph
{ .&chdVcxyS
write_nPos(); kV1vb
Utility.sleep(500); QV/";A3k
breakWhile = true; d +xA:
PEy/k.
C*O ,rm}
for(int i=0;i<nStartPos.length;i++) bpMl =_
{ n{{P3f
if(!fileSplitterFetch.bDownOver) M;qb7Mu
{ /:Y9sz uW`
breakWhile = false; F;a3
break; vpafru4
} WFj*nS^~l
} DoG%T(M!a9
if(breakWhile) ,F}r@
break; i_y:4
sVcdj|j
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//count++; >i`8R
//if(count>4) }3sN+4
// siteStop(); gV.f*E1C
} 3"vRK5Bf
SW;HjQ>V
!3HsI|$<G
System.err.println("文件下载结束！"); 7(@(Hm
} &<=e_0zT
catch(Exception e){e.printStackTrace ();} `A"Q3sf%
} A:c]1
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;ct)H* y
//获得文件长度 QmHwn)Ly
public long getFileSize() 7&px+155
{ Q!x`M4
int nFileLength = -1; tO4):i1
try{ (h|ch#
URL url = new URL(siteInfoBean.getSSiteURL()); =Pj@g/25u
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); s@z{dmL
httpConnection.setRequestProperty("User-Agent","NetFox"); U,38qKE
S"{GlRpd
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int responseCode=httpConnection.getResponseCode(); vQy$[D*
if(responseCode>=400) 08O7F
{ 3/l\ <{
processErrorCode(responseCode); u6p5:oJj,
return -2; //-2 represent access is error ,,}sK
} ,wlbIl~
1wbTqc
($:y\,5(9I
String sHeader; 0IpST
iz$FcA]
& L3UlL
for(int i=1;;i++) t5n2eOy~T
{ &!6DC5
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); T|!D>l'
//Utility.log(in.readLine()); . Jb?]n
sHeader=httpConnection.getHeaderFieldKey(i); 2pjW,I!`
if(sHeader!=null) 33,;iE
{ r/^tzH's
if(sHeader.equals("Content-Length")) 0w'|d@*wV
{ }ymc5-
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); ;fj9n-
break; IJldN6&\q
} 2mSD"[%
} 7:h<`_HT(X
else #TIX_RXh
break; ^IYJEqK
} q`cEA<~S
} *[VEF
catch(IOException e){e.printStackTrace ();} PK_Fx';ke^
catch(Exception e){e.printStackTrace ();} K`~BL=KI
Vj/fAHR`>'
^W5>i[
Utility.log(nFileLength); QP+c?ct}hF
'xsbm^n6a&
:cEd[Jm9
return nFileLength; G{/;AK
} pK<%<dIc
,;7`{Nab
E3LBPXK
//保存下载信息（文件指针位置） W\'Nv/L
private void write_nPos() 1Jl{1;c
{ 7F=2t_2O
try{ P&,hiGTDi
output = new DataOutputStream(new FileOutputStream(tmpFile)); >/8ru*Oc
output.writeInt(nStartPos.length); I'xC+nL@
for(int i=0;i<nStartPos.length;i++) R04.K!
{ .r7D)xNa@
// output.writeLong(nPos); Q6eN+i2 ;
output.writeLong(fileSplitterFetch.nStartPos); y{YXf!AS
output.writeLong(fileSplitterFetch.nEndPos); v3?kFd7%H~
} hTDV!B-_(
output.close(); " \`BPN
} W0C{~|e
catch(IOException e){e.printStackTrace ();} HgYc@P*b
catch(Exception e){e.printStackTrace ();} @l)\?IEF@f
} (rAiDRQ[
)\D2\1e(c
dFx2>6AZt
//读取保存的下载信息（文件指针位置） fV*}c`
private void read_nPos() Go-wAJ>
{ E]\D>[0O
try{ :m]/u( /N
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); #NWZk.S
int nCount = input.readInt(); O>nK,.
nStartPos = new long[nCount]; ZGA)r0] P`
nEndPos = new long[nCount]; :jBZK=3F>
for(int i=0;i<nStartPos.length;i++) T!Xm")d
{ 1]_?$)$T
nStartPos = input.readLong(); <"hb#Tn
nEndPos = input.readLong(); <V7SSm
} j.<:00<
input.close(); 5?Uo&e
} Tt{U"EFO
catch(IOException e){e.printStackTrace ();} A*rZQh b[
catch(Exception e){e.printStackTrace ();} u82h6s<'W
} IO^:FnJJv
~g*Y, Y
@bc[ eas
private void processErrorCode(int nErrorCode) 79TPg
{ +.S#=
System.err.println("Error Code : " + nErrorCode); J 5Wz4`'
} j?Cr31
y>>vGU;
qUifw @
//停止文件下载 _{lx*dq
public void siteStop() @c6"RHG9
{ \s.1R/TyD
bStop = true; P#w}3^
for(int i=0;i<nStartPos.length;i++) r hiS
fileSplitterFetch.splitterStop(); m$7x#8gF
+8Of-ZUx
m5X3{[a:
} u+I3IdU3
} wy,Jw3
//负责部分文件的抓取 J"/JRn
**FileSplitterFetch.java 5dg-d\6S
*/ UN-T^
package NetFox; BjH~Ml2
=Dh$yC-Zr
<P|`7wfxE
import java.io.*; Ko1AaX(I'+
import java.net.*; [u/zrpTk
'9IP;
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public class FileSplitterFetch extends Thread { CWE Ejl
@*CAn(@#N
;[;)P tFz\
String sURL; //File URL LN@lrC7X
long nStartPos; //File Snippet Start Position C$$"{FfgU"
long nEndPos; //File Snippet End Position q:TZ=bs^
int nThreadID; //Thread's ID fn1 ?Qp|
boolean bDownOver = false; //Downing is over H;b8I
boolean bStop = false; //Stop identical cYZwWMzp
FileAccessI fileAccessI = null; //File Access interface wrz+2EP`
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public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException "}S9`-Wd|
{ [54@irH
this.sURL = sURL; IW5*9)N?
this.nStartPos = nStart; [>b '}4
this.nEndPos = nEnd; 2q`)GCES~
nThreadID = id; +CsI,Uf4*
fileAccessI = new FileAccessI(sName,nStartPos);//定位 >v^2^$^u
} c+@d'yR
o,*folL
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public void run() 4(` 2#
{ 9X 5*{f Y
while(nStartPos < nEndPos && !bStop) a/`c ef
{ T)b3N|ONB
iifc;62
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try{ ) 1lJ<g#
URL url = new URL(sURL); Iq4Kgc
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 4?9soc
httpConnection.setRequestProperty("User-Agent","NetFox"); (Wm/$P;
String sProperty = "bytes="+nStartPos+"-"; &,W_#l{
httpConnection.setRequestProperty("RANGE",sProperty); D}zOuB,S
Utility.log(sProperty); gGtep*k
SRA|7g}7W
1Pud,!\%q
InputStream input = httpConnection.getInputStream(); pieU|?fQ
//logResponseHead(httpConnection); p<Zs* @
Jo6~r-
]I{qp~^#n
byte[] b = new byte[1024]; n.2E8m/
int nRead; vDu0
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) tb-OKZq
{ }4bB7,j
nStartPos += fileAccessI.write(b,0,nRead); p{mxk)A
//if(nThreadID == 1) '#cT4_D^lI
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); zznPD%#Sc
} K$MJ#Zx^
s=H/b$v
F|]o9&/<]
Utility.log("Thread " + nThreadID + " is over!"); ATYQ6E[{MV
bDownOver = true; O ,Pl7x%tK
//nPos = fileAccessI.write (b,0,nRead); ,omp F$%
} MZUF! B
catch(Exception e){e.printStackTrace ();} ) xfc-Q
} hRuo,FS#:
} 2x<Qt2"
l}2%?d
;kyL>mV{
//打印回应的头信息 xJ[k#?T'
public void logResponseHead(HttpURLConnection con) ,<uiitOo
{ GL;x:2XA
for(int i=1;;i++) w8m8r`h
{ ?)Czl4J
String header=con.getHeaderFieldKey(i); Sy+]SeF&
if(header!=null) j61BP8E
//responseHeaders.put(header,httpConnection.getHeaderField(header)); cXLV"d
Utility.log(header+" : "+con.getHeaderField(header)); E<zT
else 48 c D3w
break; w-0O j
} y~]IVl"
} C0t+Q
c:?#zX
c:h.J4mv
public void splitterStop() DJ mQZ+{2
{ Z!]U&Ax`Z
bStop = true; 9%3 r-U=
} -CU7u=*b
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I |<+'G
} 6yu*a_
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ga{25q}"
/* X5L(_0?F1
**FileAccess.java (2O} B.6
*//文件访问(定位，写) LRCS)UBY(.
package NetFox; r7Q:l ?F2
import java.io.*; |L.~Amd
Mk'n~.mb
#5ohmp,u
public class FileAccessI implements Serializable{ I7q?V1fu4
,rH)}C<Q+
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 +]S;U&vQ
RandomAccessFile oSavedFile; EMW4<na[
long nPos; JR a*;_
S0Bl?XsD_
d5sGkR`(
public FileAccessI() throws IOException XC$+ `?
{ 8)-t91hkL
this("",0); -;@5Ua1uf
} VH7iH|eW
_~wV{ yp
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public FileAccessI(String sName,long nPos) throws IOException 1(:=jOfk
{ rd"]@~v1
oSavedFile = new RandomAccessFile(sName,"rw"); F;MT4*4
this.nPos = nPos; <_sT]?N#
oSavedFile.seek(nPos); RZV1:hNN
} 8Snq75Q<
)HzITsFZKT
ek{PA!9Sk
public synchronized int write(byte[] b,int nStart,int nLen) 2,XqslB)
{ ]:E! i^C`Z
int n = -1; ?CUp&L0-"
try{ :S+U}Sm[
oSavedFile.write(b,nStart,nLen); -YRL>]1
n = nLen; YW$x:
} dWB8
catch(IOException e) jzJ1+/9
{ 2;?wN`}5g=
e.printStackTrace (); "mP*}VF
} ' ! UF&
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return n; 9Pob|UA
} bF Y)o Z
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} 6B;_uIq5
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Lx:9@3'7'
/* 9CU6o:'fW
**SiteInfoBean.java E=1/
*/ Q!+{MsZ
package NetFox; &v9PT!R~
dT@SO
SE}RP3dF!
public class SiteInfoBean { sO4}kxZ
9uq+Ve>
8apKp?~yW
private String sSiteURL; //Site's URL Hj4w i|
private String sFilePath; //Saved File's Path x+:,b~Skk
private String sFileName; //Saved File's Name 2wuW5H8w{
private int nSplitter; //Count of Splited Downloading File Q0"F>%Cn
fddbXs0Sn
QWW7I.9r
public SiteInfoBean() (Q]Y> '
{//nSplitter的缺省值为5 4\'81"ei
//default value of nSplitter is 5 Z=t#*"J
this("","","",5); q(ET)xCeD
} pffw5Tc
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public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) _M]rH<h
{ K^qUlyv
sSiteURL= sURL; \PMKmJX0O
sFilePath = sPath; > %cWTC
sFileName = sName; 9@z|2z2\G
this.nSplitter = nSpiltter; $?AUk
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u*-<5&X
} rNzhP*Fw
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m6Cd^'J9^
public String getSSiteURL() /'=^^%&:B
{ 89- 8v^ Pq
return sSiteURL; ~CdseSo9
} ?eVuz x
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public void setSSiteURL(String value) *DI:MBJY
{ }!7DF
sSiteURL = value; k$x 'v#
} 8 8=c3^
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R6@~
public String getSFilePath() a~eLkWnh<k
{ @?cXa: tX
return sFilePath; <<zz*;RJJ
} 6M vRR
7 }MJK)
-0IFPL8
public void setSFilePath(String value) V45Udwp^
{ |e;z"-3
sFilePath = value; >iWf7-:
} Cv(N5mA2
Ho8.-QSG
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public String getSFileName() 2c`=S5
{ ?gMrcc/{
return sFileName; RqjDMN:
} TN@JPoH
+-YuBVHL
T&MS_E&;
public void setSFileName(String value) M*@aA XM
{ H{Y=&#%d
sFileName = value; rbZ6V :
} OO+#KyU
v4a4*rBI"
#~-&&S4a.J
public int getNSplitter() CJtjn
{ `1}?{ud
return nSplitter; FITaL@{c
} n zrCOMld
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;Owu:}
public void setNSplitter(int nCount) 'CAukk|
{ i|{nj\6w^
nSplitter = nCount; 0uJzff!|
} DCzPm/#b
} lJY=*KB(6
<RVtLTd/
{1U*:@j
/* *k]S{]Y
**Utility.java z2q5f:d8
*/ 7^TXlWn^G
package NetFox; \bQ!>l\
R*{?4NKG
$yqq.#1
public class Utility { Ty:Ir
YYr&r.6
Q|z06_3i
public Utility() p#BvlS=D
{ =(5GU<}
i[^lJ)[>N
&j@J<*k
} 5Zm_^IS
l@J|p#0q
//线程睡眠 RGuHXf
public static void sleep(int nSecond) j3-6WUO
{ >^GCSPe
try{ GE+csnA2
Thread.sleep(nSecond); K0H!Ds9
} J6Nw-qF
catch(Exception e) T*~)9o
{ "?&bh@P&
e.printStackTrace (); 29657k8
} 4 Wd5Goe:
} Hz3X*G\5b
!!O{ ppM
//日志 z\d2T%^:g(
public static void log(String sMsg) VgTI2
{ NWN)b&}
System.err.println(sMsg); `(suRp8!
} `+;oo B
zP'pfBgbJW
< LAD
public static void log(int sMsg) LVl0:!>~
{ w}q@VVB%
System.err.println(sMsg); >6834e
} Y]Vc}-a(h
} }lpm Hvs
2Wf qgR[3
,[1`'nN@g
/* koY8=lh/
**TestMethod.java q0Lt[*q3R
*/ o(NyOC
package NetFox; tsVhPo]e0
cB=u;$k@*
3CPOZZ
public class TestMethod { @W- f{V
lj*913aFh
Z9~Wlt'?
public TestMethod() [F{a-i-
{ ///xx/weblogic60b2_win.exe )K3 vzX
try{ tg3JU\
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); U(LR('-h
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); |L{dQ)-'l
SiteFileFetch fileFetch = new SiteFileFetch(bean); =e{KtX.
fileFetch.start(); &'\+Z
} gt(nZ
catch(Exception e){e.printStackTrace ();} A8(PI)Ic.
qk1D#1vl
&7u Ra1/R
} #h|< >
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yP]W\W'
public static void main(String[] args) R3`W#`
{ x#mk[SV
new TestMethod(); IjAity.Xrq
} zNJyF;3
} ulo7d1OVkJ
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