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)); (".`#909
} /+"BU-aQk
for(int i=0;i<nEndPos.length-1;i++) HpSgGhL'J&
{ ]b.@i&M
nEndPos = nStartPos[i+1]; IpoZ6DB$
} |Ag~k? QC
nEndPos[nEndPos.length-1] = nFileLength; 7sC$hm]
} O=MO M
} be$wGO=Ts
>VE,/?71@
L<J';#BD
//启动子线程 %TPnC'2
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; Zu_m$Mx
for(int i=0;i<nStartPos.length;i++) Q68&CO(rE
{ W~POS'1
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), /.aZXC$]
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), +AtZltM i
nStartPos,nEndPos,i); IW Lv$bPZ/
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); f&js,NU"
fileSplitterFetch.start(); )2g\GRg6
} 9|D!&=8
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 6QLWF@
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); }7IS:"tu
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", hc"+6xc
nEndPos = " + nFileLength); H"WkyvqXb
// fileSplitterFetch[nPos.length-1].start(); ]N:SB
/$! /F@^
6sRn_y
//等待子线程结束 gJ+MoAM"
//int count = 0; p=coOWOQ
//是否结束while循环 Ii?<Lz
boolean breakWhile = false; & *B@qQ
,`^B!U3m
8,a&i:C
while(!bStop) .*r?zDV
{ 7F>5<Gv:-
write_nPos(); }C}~)qaZv+
Utility.sleep(500); xA`Q4"[I
breakWhile = true; (NFq/w%
5:hajXd
[j?n}D@L
for(int i=0;i<nStartPos.length;i++) U!XC-RA3 _
{ SWz+.W{KQ"
if(!fileSplitterFetch.bDownOver) ES;7_.q
{ "e69aAA,
breakWhile = false; q+19EJ(
break; Zi|MWaA.f
} Zuo7MR
} ^Gq4Yr
if(breakWhile) I .p26
break; 2rB$&>}T
V.XHjHT
zg.'
//count++; Kg VLXI6
//if(count>4) (Vf&,b@U_
// siteStop(); T8GxoNm
} c;xL.
d}EGI
VSx[{yn
System.err.println("文件下载结束！"); 1U;je,)
} e=o<yf9>Q
catch(Exception e){e.printStackTrace ();} \wCj$-;Jt
} MQ$[jOAqP
e-ljwCD
ua/A &XQx
//获得文件长度 ecA:y!N
public long getFileSize() _SY<(2s]B
{ mv/'H^"[_
int nFileLength = -1; `4'v)!?
try{ rqxoqcZ
URL url = new URL(siteInfoBean.getSSiteURL()); mEa\0oPGB
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); k_r12Bu
httpConnection.setRequestProperty("User-Agent","NetFox"); :2^%^3+V
KqP!={>"
fZ`b~ZBwIj
int responseCode=httpConnection.getResponseCode(); JX7_/P
if(responseCode>=400) @N7X(@O
{ Tsxl4ZK
processErrorCode(responseCode); 'VS!<
return -2; //-2 represent access is error W#P)v{K
} _k\*4K8L
-7fsfcGM$
beRpA;
String sHeader; B[Fx2r`0
R^iF^IB
<ap%+(!I
for(int i=1;;i++) ^o,P>u!9
{ Vk5}d[[l
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); "diF$Lj
//Utility.log(in.readLine()); `J|bGf#
sHeader=httpConnection.getHeaderFieldKey(i); "9!ln
if(sHeader!=null) WogJ~N,d53
{ M`-#6,m3
if(sHeader.equals("Content-Length")) X~*1
{ U; JZN
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); \U(qv(T
break; n[|&nv6x
} 1#qyD3K
} VU J*\Sg
else Ck%nNy29
break; eGHxiC
} JfxD-9U^>u
} Jt\?,~,
catch(IOException e){e.printStackTrace ();} 3BAls+<p o
catch(Exception e){e.printStackTrace ();} q!\K!W\
6{B$_Usg
|a%&7-;
Utility.log(nFileLength); -GLI$_lLF
ts`c_hH,1'
{f((x1{HZx
return nFileLength; ^q-]."W]t~
} q(p]6Ha|
fW~r%u .y
4:.yE|@h[
//保存下载信息（文件指针位置） {u{n b3/jl
private void write_nPos() U$Z)v1&{
{ 5%,J@&5G s
try{ >'iXwe-
output = new DataOutputStream(new FileOutputStream(tmpFile)); 1//d68*"
output.writeInt(nStartPos.length); NYA,
for(int i=0;i<nStartPos.length;i++) ~2@+#1[g8z
{ 0-M.>fwZ=
// output.writeLong(nPos); \b95CU
output.writeLong(fileSplitterFetch.nStartPos); nsIx5UA_n
output.writeLong(fileSplitterFetch.nEndPos); Azvj(j
} 3jZPv;9OC
output.close(); es 8%JTi
} &<2~7?$!
catch(IOException e){e.printStackTrace ();} H:Y?("k
catch(Exception e){e.printStackTrace ();} @W[`^jfQ
} X31[
|=fa`8mG
Au<NUc 2
//读取保存的下载信息（文件指针位置） a'u:1C^\
private void read_nPos() s_S[iW`l=
{ ZjF5*A8l
try{ pKJ0+mN#"
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); :c[iS~ ~Y
int nCount = input.readInt(); w/BaaF.0
nStartPos = new long[nCount]; _^]2??V
nEndPos = new long[nCount]; F6J,:
for(int i=0;i<nStartPos.length;i++) [vh&o-6
{ L9ECF;)
nStartPos = input.readLong(); )65 o
nEndPos = input.readLong(); O W`yv
} M6l S2
input.close(); J:LwO
} d|#sgGM<8
catch(IOException e){e.printStackTrace ();} 6yH(u}!.
catch(Exception e){e.printStackTrace ();} ~3bH2,{L[
} ~iI4v#0
wXI6KN-
$L%gQkz_
private void processErrorCode(int nErrorCode) '0|0rwx
{ xo3bY6<n
System.err.println("Error Code : " + nErrorCode); V_+XZ+7Lx}
} 8 :B(}Y4K
3pg_`
Hj\>&vMf
//停止文件下载 m%au* 0p
public void siteStop() "=8= G
{ qM%l
bStop = true; $fZVh%
for(int i=0;i<nStartPos.length;i++) w6FtDl$
fileSplitterFetch.splitterStop(); 3H"bivK
vdA3
7bJAOJ'_
} xh|NmZg
} v3>jXf
//负责部分文件的抓取 ~Y;_vU
**FileSplitterFetch.java t$+[(}@+
*/ Z ,4G'[d
package NetFox; 86+nFk
bz$)@gLc
a2Q_K2t
import java.io.*; 4FLL*LCNX
import java.net.*; c*R?eLt/
3>O=d>
F&pJ faig
public class FileSplitterFetch extends Thread { BhFyEY(
h|m>JDxn
w K)/m`{g
String sURL; //File URL o+-G@16
long nStartPos; //File Snippet Start Position Nr6[w|Tzd
long nEndPos; //File Snippet End Position oY Y?`<N#
int nThreadID; //Thread's ID *F[;D7sZ~
boolean bDownOver = false; //Downing is over 3pQ^vbQ"
boolean bStop = false; //Stop identical Qmbl_#
FileAccessI fileAccessI = null; //File Access interface 9qe<bds1
JSKAlw
&.D#OnRh9
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException %#gHa
{ XNZW J
this.sURL = sURL; s,~)5nL
this.nStartPos = nStart; Iq/V[v
this.nEndPos = nEnd; *Y"j 0Yob
nThreadID = id; H!6nIS9yxt
fileAccessI = new FileAccessI(sName,nStartPos);//定位 V'n4iM
} ~# ~XDcc
(Qf"|3R4
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public void run() {[W [S@+
{ cHr.7 w
while(nStartPos < nEndPos && !bStop) uPZ<hG#K
{ 78o>UWA:
Fkq;Q
0{0A,;b
try{ 6KpG,%2L#
URL url = new URL(sURL); b`%(.&
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); /U1&#"P
httpConnection.setRequestProperty("User-Agent","NetFox"); w]-,X`
String sProperty = "bytes="+nStartPos+"-"; H<YhO&D*u
httpConnection.setRequestProperty("RANGE",sProperty); 7|vB\[s
Utility.log(sProperty); ;`CNe$y
A08b=S
FEoH$.4
InputStream input = httpConnection.getInputStream(); ;_]Z3
//logResponseHead(httpConnection); 6B pm+}
Rq,ST:
Wu:@+~J.h
byte[] b = new byte[1024]; ;`p!/9il
int nRead; .WeP]dX%:f
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) %BV2 q
{ )'pc1I
nStartPos += fileAccessI.write(b,0,nRead); ?A]@$
//if(nThreadID == 1) c+_F}2)
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); '5:P,1tWU
} 6e%|.}U
QAI!/bB
vbn'CY]QU
Utility.log("Thread " + nThreadID + " is over!"); qYi<GI*|@
bDownOver = true; gr&Rkuyfv
//nPos = fileAccessI.write (b,0,nRead); <;T$?J9
} {\87]xJ
catch(Exception e){e.printStackTrace ();} M?yWFqFt9m
} }3rWmo8V
} %\uEV
aucQZD-_"
F|ib=_)3
//打印回应的头信息 N=?! ~n9Q-
public void logResponseHead(HttpURLConnection con) fBZ\,
{ 3aK/5)4|B
for(int i=1;;i++) BAUo`el5
{ !uno!wUIYd
String header=con.getHeaderFieldKey(i); `;'fCO!
if(header!=null) slV7,4S&!
//responseHeaders.put(header,httpConnection.getHeaderField(header)); y%9Q]7&=
Utility.log(header+" : "+con.getHeaderField(header)); qrq9NPf
else P2Or|_z
break; KR4vcI[4
} tOu:j [
} x>E**a?!L
X*cf|g
@C}Hx;f6
public void splitterStop() T-'B-g
{ 9YtdE*,k
bStop = true; K% Gbl#
} 4_A9o9&_Rh
`6t3D&.u0
1|PmZPKq9n
} #h#Bcv0 Z
|>Xw"]b;
TYs#v/)I
/* .x^`y2'U
**FileAccess.java 1V@\L|Y
*//文件访问(定位，写) cv'Fc
package NetFox; VB+sl2V<h
import java.io.*; Xc^7
s\-^vj3
,;_D~7L
public class FileAccessI implements Serializable{ N,><,7!q$,
0 CJ4]mYl
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 ji &*0GJQ
RandomAccessFile oSavedFile; )kE(%q:*P$
long nPos; rI[Lg0S
]:Q7Gys
d\cwUXf J
public FileAccessI() throws IOException ,0~/ Cn
{ /&+6nOP
this("",0); qM$~5uu
} Nr#Y]9nA
`tCOe
})l+-H"
public FileAccessI(String sName,long nPos) throws IOException yk5T"#'+
{ }UzO_&Z#6
oSavedFile = new RandomAccessFile(sName,"rw"); <IF\;,.c
this.nPos = nPos; jZ'y_
oSavedFile.seek(nPos); <N{pMz
} FZ)Y<r8|s
7{vnhl(Z
~YuRi#CTD:
public synchronized int write(byte[] b,int nStart,int nLen) |sw&sfH[FD
{ ; md{T'
int n = -1; 9u'hCi(
try{ 3,K*r"=
oSavedFile.write(b,nStart,nLen); F7(~v2|
n = nLen; lRn6Zh
} J-W,^%
catch(IOException e) Y=gj{]4
{ ]c8$%
e.printStackTrace (); 9iQcK&D 2
} RfT#kh/5
!(!BW9Zt+
6]|NB&
return n; tk^1Ga3
} VD\pQ.=
@"~Mglgw
?-FSDNQ
} ]`D(/l'
^}2 ie|
Qa,^;hZWS
/* !U"1ZsO)l
**SiteInfoBean.java (u]ajT
*/ Bc4{$sc"O
package NetFox; J! 4l-.-
'_n{+eR74
dt"[5;_P`
public class SiteInfoBean { VA _O0y2
5L<}u`0J
?=<vC
private String sSiteURL; //Site's URL }P$48o VY
private String sFilePath; //Saved File's Path uP/WRQ{rW>
private String sFileName; //Saved File's Name jl<rxO?-F
private int nSplitter; //Count of Splited Downloading File Rk PY@>
s0Ii;7fA{
&)vX7*j
public SiteInfoBean() (8s]2\/Ar
{//nSplitter的缺省值为5 r\Wp\LfY&{
//default value of nSplitter is 5 j$*]'s&_hZ
this("","","",5); -Uz xs5Zl
} 1K'0ajl1A
q{UP_6OF
m_H$fioha,
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) R]%ZqT{PS
{ h2Ifq!(:
sSiteURL= sURL; oHmU|
sFilePath = sPath; x8T5aS
sFileName = sName; ]{OEU]I@
this.nSplitter = nSpiltter; XN"V{;OP1
Z'GOp?
/UjRuUC]
} NQ<~$+{
NDB]8C
yZ,k8TJ",
public String getSSiteURL() `n:IXD5'
{ A.vcE
return sSiteURL; _Z6/r^c
} r0kA47
J+&AtGq]u
J p .wg
public void setSSiteURL(String value) +asJV1a
{ t8s1d
sSiteURL = value; l)z15e5X
} Q8M&nf
%^"Tz,f
IxCEE5+`%
public String getSFilePath() .i/]1X*;r^
{ lN+NhPF
return sFilePath; i^uC4S~
} *&e+z-E
JRA.,tQc
_]tR1T5e
public void setSFilePath(String value) .jr1<LE
{ >qx~m>2|8]
sFilePath = value; g\ @nA4
} n/s!S &
*6Rl[eXS
'N5qX>Ob
public String getSFileName() 1X2oz
{ m7kDxs(KO
return sFileName; U:MkA(S%c
} <_ */
_\"P<+!
#rV=!j||
public void setSFileName(String value) @DkPJla&
{ ok'0Byo
sFileName = value; )1j~(C)E8
} }QncTw0
5"y p|Yl
svyC(m)'
public int getNSplitter() K4n1#]8i
{ &tD`~
return nSplitter; ?9!tMRb
} N) {
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{<~XwJ.
public void setNSplitter(int nCount) z.Y7u3K.8
{ HcHfwLin0
nSplitter = nCount; $2>tfKhtA
} 2>fG}qYy$
} yL.si)h(p
yixW>W}
WGG|d)'@
/* B0q![
**Utility.java 8t}=?:B+{
*/ ^Sy\<
package NetFox; 2I?HBz1v
j#&sZ$HQ4
4>Uo0NfL
public class Utility { 4g\a$7r
]vQo^nOo
PBn(k>=+
public Utility() (fh:q2E#
{ NFLmM
B[4y(Im
$'9r=#EH
} DGHX:Ft#
{yt]7^
//线程睡眠 W%Rh2l
public static void sleep(int nSecond) ~8pf.^,fi
{ QJdSNkc6
try{ AV d
Thread.sleep(nSecond); @dCu]0oNI
} ^#3$C?d
catch(Exception e) gyCb\y+\a
{ YXIDqTA+
e.printStackTrace (); ^ ?tAt3dMI
} mkE*.I0=
} IH~H6US
5\=9&{WjND
//日志 ts?b[v
public static void log(String sMsg) &p;};n
{ jcq(=7j
System.err.println(sMsg); lBG*P>;
} 82J0t}:U
'12|:t&7
& p_;&P_
public static void log(int sMsg) ` V^#Sb
{ bk6$+T=>
System.err.println(sMsg); sWavxh8A
} ziH2<@
} j~Gu;%tq
bq(*r:`"
g=U?{<8.m
/* X'?v8\mPK
**TestMethod.java &2xYG{Z
*/ Jh466; E
package NetFox; [0&Lvx
lh#GD"^(w&
wkJB5i^<w
public class TestMethod { GV[%P
_L$)~},cT
lC_zSmT
public TestMethod() Cg{$$&_(Hj
{ ///xx/weblogic60b2_win.exe qsk71L
try{ er#we=h
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); \o % ES
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); r`B+ KQ4
SiteFileFetch fileFetch = new SiteFileFetch(bean); e#nTp b
fileFetch.start(); 3&y u
} =]zPUzr,|
catch(Exception e){e.printStackTrace ();} --^D)n
rXm!3E6JL
A\#?rK
} ~36c0 =
*(>$4$9n
]oya<C6pR
public static void main(String[] args) @nc!(P7_
{ \3LD^[qi
new TestMethod(); "5y^s!/
} FBY~Z$o0.
} l&|{uk
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