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)); |\}&mBR
} w}20l F
for(int i=0;i<nEndPos.length-1;i++) h+\+9^l6|
{ `7D]J*?`
nEndPos = nStartPos[i+1]; Jn|sS(Q}
} l+ ,p=
nEndPos[nEndPos.length-1] = nFileLength; )a7nr<)aU
} z`Jcpt
} eq" eLk6h
mM[KT} A
.8GX8[t
//启动子线程 :eH*biXy}2
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; CI#6r8u
for(int i=0;i<nStartPos.length;i++) mBwM=LAZ
{ Za110oF
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), S3?Bl'
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), S^8C\ E
nStartPos,nEndPos,i); VYR<x QA
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 0I v(ioB=
fileSplitterFetch.start(); `i2:@?Kl9
} .S_7R/2(?
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), VxP cC+
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); t6,bA1*5y
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", cko^_V&x
nEndPos = " + nFileLength); wB(X(nr
// fileSplitterFetch[nPos.length-1].start(); !&eKq?P{j
|&oTxx$S
M1mx{<]A
//等待子线程结束 {py"Ob_
//int count = 0; sBq-"YcjR
//是否结束while循环 v 1.8]||^
boolean breakWhile = false; /g`!Zn8a
69"4/n7B?
u\y$<
while(!bStop) GXnrVI
{ ;],Js1m
write_nPos(); @zCp/fo3
Utility.sleep(500); d:vuRK4+
breakWhile = true; S{Q2KD
7WMF8(j5
nb~592u
for(int i=0;i<nStartPos.length;i++) U[R[VY7
{ f=EWr8mno
if(!fileSplitterFetch.bDownOver) v[2N-
{ '8"nXuL-
breakWhile = false; eY V Jk7
break; ?onEqH>
} '>^!a!<G
} c;B:o
if(breakWhile) 9_b_O T
break; u9*7Buou^
aN;c.1TY
K%g_e*"$
//count++; 'Ul^V
//if(count>4) lD#S:HX
// siteStop(); g7;OZ#\
} XOoz.GSQ
Djr/!j
,Dy9-o
System.err.println("文件下载结束！"); tuslkOE#
} 20 Z/Y\
catch(Exception e){e.printStackTrace ();} i*)BFV_-
} 0F%/R^mw
[9;[g~;E%m
4J{W8jX
//获得文件长度 D=jtXQF
public long getFileSize() 7$JOIsM
{ rNoCmNm
int nFileLength = -1; ?dyt!>C
try{ 4[ *G
URL url = new URL(siteInfoBean.getSSiteURL()); 5D <
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); MAcjWb~f
httpConnection.setRequestProperty("User-Agent","NetFox"); ~='}(Fg:
v[\Z^pccgj
YM,UM>
int responseCode=httpConnection.getResponseCode(); bcYGkvGbO
if(responseCode>=400) GD1L6kVd1
{ 2[CHiB*>
processErrorCode(responseCode); rM`z2*7%d
return -2; //-2 represent access is error H-qbgd6&>R
} jfU$qo!gi
717OzrF}A?
}1mkX\wWP
String sHeader; "uP~hFA7M
JYR^k=
=bOMtQ]
for(int i=1;;i++) 13p.dp`
{ cz1 m05E
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); Ww0dU_
//Utility.log(in.readLine()); =>-W!Of
sHeader=httpConnection.getHeaderFieldKey(i); 8I7JsCj
if(sHeader!=null) s[;1?+EI
{ "9IR|
if(sHeader.equals("Content-Length")) X2mZ~RB(p
{ pD]2.O
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); q\/xx`L
break; AHzm9U @
} 5^Ny6t
} u/apnAW@M
else ZmvtUma
break; (\%J0kR3[
} }vd72PB
} lXRB"z
catch(IOException e){e.printStackTrace ();} MM*9Q`cB
catch(Exception e){e.printStackTrace ();} eB9F35[
v.53fx
? CU;
Utility.log(nFileLength); R(s[JH(&
H<"EE15
YbF}>1/"
return nFileLength; ma6Wr !J
} n5Mhp:zc,
EX@Cf!GjN
|fY#2\)Yx
//保存下载信息（文件指针位置） #V.u[:mO
private void write_nPos() XEUS)X)
{ qga\icQr
try{ L>pSE'}
output = new DataOutputStream(new FileOutputStream(tmpFile)); ~i0>[S3'
output.writeInt(nStartPos.length); O&Y22mu
for(int i=0;i<nStartPos.length;i++) gZ us}U
{ ir5eR}H
// output.writeLong(nPos); ]/|DCxQ
output.writeLong(fileSplitterFetch.nStartPos); #!>`$
output.writeLong(fileSplitterFetch.nEndPos); 0x# V
} s >k4G
output.close(); 1ZXRH;J40
} PHMp,z8
catch(IOException e){e.printStackTrace ();} !1mAq+q!
catch(Exception e){e.printStackTrace ();} ypNeTR$4
} ; hU9_e
CoV@{Pi
.uB[zJc
//读取保存的下载信息（文件指针位置） C't%e
private void read_nPos() 6n/KL
{ rS0#]Gg
try{ Hp@cBj_@P2
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); ~ujg250.L
int nCount = input.readInt(); X{iidTW`xv
nStartPos = new long[nCount]; @ev^e!B
nEndPos = new long[nCount]; +&*>FeJY
for(int i=0;i<nStartPos.length;i++) a YY1*^
{ u4xJ-Vu
nStartPos = input.readLong(); KP!7hJhw
nEndPos = input.readLong(); nyZ?m
} 'i;ofJ[.c
input.close(); ~Fo`Pr_
} @"iNjqxh
catch(IOException e){e.printStackTrace ();} z'zC
catch(Exception e){e.printStackTrace ();} GYonb)F
} OkphbAX
D"K!ELGW
u@aM8Na
private void processErrorCode(int nErrorCode) Q;@w\_OR
{ HS|x
System.err.println("Error Code : " + nErrorCode); xEB4oQ5
} v%QCp
<#~n+,
aqwW`\
//停止文件下载 Lve$H(GHT
public void siteStop() n&8N`!^o
{ S;BMM8U
bStop = true; nb@<UbabW}
for(int i=0;i<nStartPos.length;i++) Y'y$k
fileSplitterFetch.splitterStop(); &#@"^(} 6
,88%eX|
Pd(n|t3[8
} t5QGXj
} AI .2os*
//负责部分文件的抓取 >Lz2zlZI
**FileSplitterFetch.java hG3RZN#ejq
*/ <4;f?eu
package NetFox; `U;V-
ik0w\*
^1ks`1
import java.io.*; 6,]2;'
import java.net.*; ?#__#
#|lVQ@=
QYWl`Yqf
public class FileSplitterFetch extends Thread { l> >BeZ
5a* Awv}
.\)p3pC)
String sURL; //File URL FFH{#|_1
long nStartPos; //File Snippet Start Position 94XRf"^
long nEndPos; //File Snippet End Position ) |hHbD^V
int nThreadID; //Thread's ID Uzk_ae
boolean bDownOver = false; //Downing is over cr{dl\Na
boolean bStop = false; //Stop identical hy:K) _
FileAccessI fileAccessI = null; //File Access interface Pv@;)s(-
*8 ]
U9AtC.IG!
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException [92bGR{
{ FRTvo
this.sURL = sURL; #p=Wt&2
this.nStartPos = nStart; F#{PJ#
this.nEndPos = nEnd; gwYTOs^
nThreadID = id; g:"Hg-s
fileAccessI = new FileAccessI(sName,nStartPos);//定位 /zV0kW>N
} *tT5Zt/&Sr
St1>J.k_
,I[A~
public void run() 8\Eq(o}7
{ 7M9s}b%?
while(nStartPos < nEndPos && !bStop) 5?|PC.
{ .T*7nw
$w<~W1\:
FD}>}fLv
try{ g/,O51f'
URL url = new URL(sURL); J15$P8J
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); dk2o>jI4;
httpConnection.setRequestProperty("User-Agent","NetFox"); SiJX5ydz
String sProperty = "bytes="+nStartPos+"-"; q}5&B=2pM
httpConnection.setRequestProperty("RANGE",sProperty); PiIILX{DuH
Utility.log(sProperty); /XW,H0pR
2qkC{klC^M
o6;VrpaNi
InputStream input = httpConnection.getInputStream(); GG_A'eX:I
//logResponseHead(httpConnection); z~a]dMs"(P
U0S}O(Ptr
z9KsSlS ^
byte[] b = new byte[1024]; d>7bwG+k
int nRead; g:c @
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) Th*mm3D6
{ %n#^#:
nStartPos += fileAccessI.write(b,0,nRead); jfrUOl'l
//if(nThreadID == 1) 'w7{8^Z2
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); {EupB?
} B6vmBmN
';7|H|,F
8 _[f#s`)
Utility.log("Thread " + nThreadID + " is over!"); }(XvI^K[^
bDownOver = true; c[0$8F>
//nPos = fileAccessI.write (b,0,nRead); z'X_s.9F
} :ui1]its4
catch(Exception e){e.printStackTrace ();} N:/$N@"Ge
} **O4"+Xi8
} H\!u5o&}`
cjO,#W0&f
[G|2m_
//打印回应的头信息 IN]bAd8"
public void logResponseHead(HttpURLConnection con) j|WaWnl=
{ P6 G/J-
for(int i=1;;i++) Dy^4^ J5+
{ 9P)<CD0
String header=con.getHeaderFieldKey(i); ?0Ca-T Rz
if(header!=null) f1>^kl3@P
//responseHeaders.put(header,httpConnection.getHeaderField(header)); M>k7 '@G
Utility.log(header+" : "+con.getHeaderField(header)); w02HSQ
else (;h]'I@
break; 5cQBqH]
} 9tC8|~Q
} UwQ3q
Vt4}!b(O
3B"rI
public void splitterStop() Q<``}:y|>
{ fhn0^Qc"+
bStop = true; "WYcw\@U
} 5tl}rmI`
Fk(0q/b
z_l3=7R
} [l5"'{x
ddHIP`wb
qkUr5^1
/* @+X}O/74
**FileAccess.java r5iO%JFg
*//文件访问(定位，写) I}v'n{5(
package NetFox; )3B5"b,
import java.io.*; rb\Ohv\
mLY*
Da-(D<[0
public class FileAccessI implements Serializable{ Ef`LBAfOO
$'FPst8Q<
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 :g9z^ $g
RandomAccessFile oSavedFile; JkxS1
long nPos; FvI`S>
rrwsj`
TcfBfscU
public FileAccessI() throws IOException Jp-ae0 Ewa
{ JcVq%~{M
this("",0); S s`0;D1
} /?XfVhA:A
56_KB.Ww~
Yg]f2ke
public FileAccessI(String sName,long nPos) throws IOException r&3fSx9
{ 2aje$w-
oSavedFile = new RandomAccessFile(sName,"rw"); i)(QNpv
this.nPos = nPos; Ju9v n44
oSavedFile.seek(nPos); ^:)&KV8D|
} wbS++cF<
610k#$
^&rbI,D
public synchronized int write(byte[] b,int nStart,int nLen) z:G9Uu3H(
{ 0\~Zg
int n = -1; =W|Q0|U
try{ : }IS=A
oSavedFile.write(b,nStart,nLen); sTqB%$K}
n = nLen; 7:j #1N[p
} `(a^=e5
catch(IOException e) U;q)01
{ 'Lw\nO.
e.printStackTrace (); zm.2L
} 86I*
Hf-F-~E
%ej"ZeM
return n; BmJ?VJ}Y
} }I`|*6Up
8say"Qz
Q8~pIv
} q%vUEQLBp
-)I_+N
,/ : )FV
/* t3XMQ']
**SiteInfoBean.java zLn#p]
*/ |5/[0V-vy
package NetFox; n{yjH*\Z
*sG<w%%
-/qrEKQ0U?
public class SiteInfoBean { KE3v3g<
o<'gM]$
]/']{*T1
private String sSiteURL; //Site's URL D_)vGvv3;.
private String sFilePath; //Saved File's Path T:&+#0<
private String sFileName; //Saved File's Name N.`]D)57
private int nSplitter; //Count of Splited Downloading File @&W?e?O ~G
C(P$,;6
~<U3KB
public SiteInfoBean() t}FMBGo[
{//nSplitter的缺省值为5 +J4t0x
//default value of nSplitter is 5 %dU}GYL_
this("","","",5); >dl!Ep
} N9ufTlq s
ybG)=0
i=a LC*@
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) Z%R%D*f@y
{ <<1oc{i
sSiteURL= sURL; =KZ4:d5
sFilePath = sPath; Vel;t<1
sFileName = sName; u@EM,o
this.nSplitter = nSpiltter; {EUH#':
("oA{:@d
1W g8jr's
} %ze1ZWO{
ezvaAhd{
|Q;o538
public String getSSiteURL() GXRjR\Ch
{ \d+HYLAJn
return sSiteURL; bH{aI:9Fb
} c" 7pf T
gsp7N
OQQ9R?Ll{
public void setSSiteURL(String value) k#(cZ
{ dL` +^E>
sSiteURL = value; ,f+5x]F?m
} 1#<E]<='t
}(K6 YL
hI8C XG
public String getSFilePath() g4X,*H
{ #U}U>4'
return sFilePath; d/>,U7eS[+
} WLLv a<{
$hQg+nY.
Snu;5:R
public void setSFilePath(String value) sJ/e=1*
{ g8"7wf`0k
sFilePath = value; h12wk2@P/]
} U08?*{
vWH>k+9&X
~a%hRJg
public String getSFileName() RKkI/Z0
{ =.hDf<U
return sFileName; 1}E@lOc
} A*~1Uz\t
lKUm_; m
\2xBOe-a]
public void setSFileName(String value) J\'5CG
{ ~,68S^nP)H
sFileName = value; @t8kN6.
} O97bgj]
})lT fy
YXVJJd$U
public int getNSplitter() p8dn-4
{ X);Zm7
return nSplitter; &;U7/?Q
} Q;/F0JDH
Ch9!AUiR
+~Ay h[V
public void setNSplitter(int nCount) O)uM&B=
{ 1cBhcYv"
nSplitter = nCount; xPup?oP >
} !<zzP LC
} '5/}MMT
dJ:x1j
Zw][c7%
/* x,gE$dNzy
**Utility.java u^zitW!X$
*/ 4E\ntufo
package NetFox; V55J[s*6!
=awO63j>
q)ql]iH
public class Utility { ~hslLUE
m8j-lNu
H#6^-6;/
public Utility() 2^#UO=ct
{ ;sR6dT)
?_>^<1I1
G=HxD4l
} NJf(,Mr*|
]}7rWs[|1
//线程睡眠 pEj^x[b`^
public static void sleep(int nSecond) pptM&Y
{ 6//FZ:q
try{ 7E3SvC|M
Thread.sleep(nSecond); qf`xH"$
} `u\z!x'
catch(Exception e) 9m!!b{
{ DsJn#>?Kh
e.printStackTrace (); zk'K.! `^
} J.mewD!%z
} .q`H`(QM
S?7V "LF
//日志 C<t'f(4s`u
public static void log(String sMsg) -^4bA<dCCE
{ >2CusT2
System.err.println(sMsg); b]<HhU
} VNrO(j DUv
MJKl]&
cYM~IA
public static void log(int sMsg) U+PCvl=x
{ Cz@FZb8
System.err.println(sMsg); TDFO9%2c
} V.Ba''E7
} ]vQ?]d?>a
$7n#\h
iSr`fQw#
/* 20l_ay
**TestMethod.java CLY6 YB' R
*/ afF+*\xXN
package NetFox; )@bH"
Cld<D5\|f+
8| e$
public class TestMethod { 9;]wF8h
5Z6-R}uXk
MkW1FjdP
public TestMethod() e(w/m(!Wny
{ ///xx/weblogic60b2_win.exe { w8 !K
try{ ]\RSHz
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); {LT4u]#
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); |5~wwL@LW7
SiteFileFetch fileFetch = new SiteFileFetch(bean); y,v0-o~q
fileFetch.start(); <L/M`(:=k
} XK%W^a*x
catch(Exception e){e.printStackTrace ();} }or2 $\>m
L+L"$
`Ixs7{&jU
} #K#Mv/
&#-|Yh/
+t>*l>[
public static void main(String[] args) $35,\ZO>
{ 4", )zDk
new TestMethod(); w.D4dv_H
} o9i#N
} 4Hml.|$
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