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)); Ri*mu*r\}
} =Ew77
for(int i=0;i<nEndPos.length-1;i++) n;QFy5HB8
{ Jyp7+M]
nEndPos = nStartPos[i+1]; p[;@9!t
} 8~O0P=
nEndPos[nEndPos.length-1] = nFileLength; J~h9i=4<bF
} O5:[]vIn
} Y^XZ.R
O:8Ne*L`D
e+?;Dc-SJ\
//启动子线程 tJm1Q#||
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; r?pN-x$M=
for(int i=0;i<nStartPos.length;i++) 3-)R'
{ gf^y3F[\
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), UMHFq-
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), b=SCyGxlZ5
nStartPos,nEndPos,i); 6H;\Jt
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); (?i4P5s[!
fileSplitterFetch.start(); )q[Wzx_ j<
} $2a_!/
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 6zGeGW
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); ]H<}6}Gd
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", V|/N-3M
nEndPos = " + nFileLength); ?.c:k;j
// fileSplitterFetch[nPos.length-1].start(); 6w_TL<S
=%B}8$.|
*o<|^,R
//等待子线程结束 O>9-iqP>`d
//int count = 0; v9Lf|FXo&
//是否结束while循环 k4` %.;
boolean breakWhile = false; lbh7`xCR
/XdLdA!v
&3itBQF
while(!bStop) zKh<zj
{ ViUx^e\
write_nPos(); }n +MVJ;dG
Utility.sleep(500); hI*6f3Vn(n
breakWhile = true; 'u_j5
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for(int i=0;i<nStartPos.length;i++) TiJ \J{
{ gb}ov**
if(!fileSplitterFetch.bDownOver) }^*`&Lh
{ qV-1aaA
breakWhile = false; uX6rCokr
break; & sXMB
} sXY{g0%
} o?aF
if(breakWhile) wBEBj7(y
break; c4bvJy8
7Oi<_b
gyU=v{].
//count++; +KOhDtLMG
//if(count>4) }}Gkipp
// siteStop(); '"h}l`
} .s|5AC[
q77Iq0VR
Pu'lp O
System.err.println("文件下载结束！"); BG6Lky/omz
} xFA`sAucr
catch(Exception e){e.printStackTrace ();} !yz3:Yzu
} ?iL-2I3*
EH'eyC-B<
; NO#/
//获得文件长度 H)rJ>L
public long getFileSize() c]|Tg9AW
{ ojVN-*5
int nFileLength = -1; ;)ERxMun
try{ v7D0E[)~
URL url = new URL(siteInfoBean.getSSiteURL()); VS65SxHA
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); }Q-Tw,j
httpConnection.setRequestProperty("User-Agent","NetFox"); c57`mOe/b
xX8c>p
v2YU2-X[
int responseCode=httpConnection.getResponseCode(); BLm}mb#/{
if(responseCode>=400) X@7:FzU9
{ .73sY5hdTN
processErrorCode(responseCode); x@x5|8:ga
return -2; //-2 represent access is error !"ydl2
} @}'?o_/C
~W3t(\B'
I,r0K]
String sHeader; .fK~IKA
8mO_dQ
c#@L~<
for(int i=1;;i++) }$a*XY1
{ r/QI-Cf&
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); 6HH:K0j3'
//Utility.log(in.readLine()); u5`b")a
sHeader=httpConnection.getHeaderFieldKey(i); T ^/\Rr
if(sHeader!=null) qr~zTBT] E
{ P75@Yu(
if(sHeader.equals("Content-Length")) *~.'lE%[U
{ ~x J#NC+
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); CU/Id`"tW
break; Q{ {=
} A^4#6],%v
} #.LI`nYA
else Ol;"}3*Z*
break; X& XD2o"rt
} Q{~;4+ZD
} gU?M/i2
catch(IOException e){e.printStackTrace ();} B.);Ju
catch(Exception e){e.printStackTrace ();} g$z6*bL
+Edq4QYwR
w~n+hhMF
Utility.log(nFileLength); p#>,{
yXf+dMv
W>[TFdH?
return nFileLength; vI(CX]o
} *QoQ$alHH
~Yre(8+M
LDDt=HEY4
//保存下载信息（文件指针位置） GMpg+rK
private void write_nPos() Jb)xzUhES
{ FWLLbL5t
try{ '"6*C*XS
output = new DataOutputStream(new FileOutputStream(tmpFile)); 8]4W@~c
output.writeInt(nStartPos.length); xk^`4;
for(int i=0;i<nStartPos.length;i++) /8/N
{ ]Bz.6OR
// output.writeLong(nPos); HrRw
output.writeLong(fileSplitterFetch.nStartPos); V\AF%=6}
output.writeLong(fileSplitterFetch.nEndPos); Z0M|Bv9_
} WHRBYq_
output.close(); 02^Nf7DMR
} )t,efg
catch(IOException e){e.printStackTrace ();} `mquGk|)
catch(Exception e){e.printStackTrace ();} ]zI*}(adu
} ;NGSJfn
~^o YPd52*
m;vm7]5
//读取保存的下载信息（文件指针位置） V7k!;0u v
private void read_nPos() HUel
{ ?~oc4J*>(
try{ d[p?B-7%
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); 0.B'Bvn=s2
int nCount = input.readInt(); m4R:KjN*
nStartPos = new long[nCount]; "_\77cqpTh
nEndPos = new long[nCount]; 9CZEP0i7
for(int i=0;i<nStartPos.length;i++) i~m;Ah,#
{ &B$%|~Y5
nStartPos = input.readLong(); d 0:;IUG
nEndPos = input.readLong(); sDkO!P
} TR:4$92:H
input.close(); G6X5`eLQ
} i,l$1g-i
catch(IOException e){e.printStackTrace ();} YIHGXi<"n
catch(Exception e){e.printStackTrace ();} I0_>ryA
} Qn@[{%),4
_ujhD
(,RL\1zJ
private void processErrorCode(int nErrorCode) MO|8A18B
{ )ZfbM|
System.err.println("Error Code : " + nErrorCode); l^__oam
} QL-E4]
[`1@`5SL-
\CYKj_c
//停止文件下载 :7s2M
public void siteStop() B06W(y,3Q>
{ 1:q`KkJx
bStop = true; nDz.61$[
for(int i=0;i<nStartPos.length;i++) , ksr%gR+
fileSplitterFetch.splitterStop(); W'v o?
RVr5^l;"
1\/^X>@W{
} k%;oc$0G-3
} 7<LCX{Uw
//负责部分文件的抓取 K>#QC
**FileSplitterFetch.java tl=e!
*/ D+Z2y1
package NetFox; $qiM_06
<qBM+m$|)
xqv&^,ic
import java.io.*; #eKH'fE
import java.net.*; 5#dJga/88
ZUl-&P_X
n -xCaq
public class FileSplitterFetch extends Thread { _DYe<f.
Pt/F$A{Cj
b\UE+\a&
String sURL; //File URL )vGxF}I3
long nStartPos; //File Snippet Start Position O*>`md?MH
long nEndPos; //File Snippet End Position perhR!#J
int nThreadID; //Thread's ID 9e;:(jl^
boolean bDownOver = false; //Downing is over pR!m
boolean bStop = false; //Stop identical |Pv)&'B"
FileAccessI fileAccessI = null; //File Access interface k:z)Sw
"XU)(<p
U(hIT9
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException c7]0>nU;
{ 9x#Tj/5%
this.sURL = sURL; .cr<.Ov
this.nStartPos = nStart; zOYG`:/'
this.nEndPos = nEnd; <ti,Wn.
nThreadID = id; 9r 5(
fileAccessI = new FileAccessI(sName,nStartPos);//定位 2F/oWt|w?
} NH+N+4dEO
:b,An'H
`KieN/d%
public void run() s@*i
{ {O4&HW%
while(nStartPos < nEndPos && !bStop) UXOf
{ %kuUQ%W1
Pje1,B q
jPs{Mr<
try{ 6h1pPx7zU
URL url = new URL(sURL); K}p0$Lc
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); P}he}k&IR
httpConnection.setRequestProperty("User-Agent","NetFox"); C-&s$5MzGb
String sProperty = "bytes="+nStartPos+"-"; \cHFV
httpConnection.setRequestProperty("RANGE",sProperty); _:KeSskuO
Utility.log(sProperty); {`9J8qRY
N,&bBp
S>d7q
InputStream input = httpConnection.getInputStream(); )gk tI!
//logResponseHead(httpConnection); UryHte
5YXMnYt9
,hCbx#h
byte[] b = new byte[1024]; M`?ATmYy
int nRead; )!'7!" $
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) Rpxg 5
{ {#z[iiB
nStartPos += fileAccessI.write(b,0,nRead); +a^0Q F-7
//if(nThreadID == 1) 1+xi1w}3a
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); [=>[2Ty
} 27Vx<W
CW,|l0i
D 75;Y;E
Utility.log("Thread " + nThreadID + " is over!"); \OkJX_7
bDownOver = true; E4<#6q
//nPos = fileAccessI.write (b,0,nRead); g+-^6UG
} dlMjy$/T
catch(Exception e){e.printStackTrace ();} ESuP ZB
} '2SZ]
} U}GO* +
_!%@V=
5qkyi]/U8
//打印回应的头信息 ',I$`h
public void logResponseHead(HttpURLConnection con) vQ>8>V
{ Lv *USN
for(int i=1;;i++) SGpe\P]k
{ [>lQiX
String header=con.getHeaderFieldKey(i); &H2j3De
if(header!=null) \+<=O`
//responseHeaders.put(header,httpConnection.getHeaderField(header)); d26#0Gt-4i
Utility.log(header+" : "+con.getHeaderField(header)); e/$M6l$Q*4
else ONLhQJCb
break; `*cJc6
} :e\M~n+y
} Z.N9e
k-sBf Jy\
9} ]C
public void splitterStop() _OB^ywHn.
{ q'%!qa+
bStop = true; a4",BDx
} Vr #o]v
7/dp_I}cO
b6'ZVB
} |pE ~
X rut[)H
. Fm| $x
/* q0@b d2}
**FileAccess.java \psO$TxF=
*//文件访问(定位，写) fF.+{-.
package NetFox; +B4i,]lCx
import java.io.*; R[H#av
\M~uNWv|
R_#k^P^
public class FileAccessI implements Serializable{ ,n$HTWa@0
9<5ii
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 h#uk-7
RandomAccessFile oSavedFile; Cm-dos
long nPos; h2 >a_0"
MF+F8h>/
x/%/MFK)>8
public FileAccessI() throws IOException _;:B@Z
{ j{HIdP
this("",0); ;kD Rm'(
} 0I*{CVTQj
;>Z0e`=
vH6.;j'^
public FileAccessI(String sName,long nPos) throws IOException TU9$5l/;g
{ N'?#g`*KW
oSavedFile = new RandomAccessFile(sName,"rw"); K\5/||gi
this.nPos = nPos; TZarI-A
oSavedFile.seek(nPos); S*H @`Do%d
} +aOX{1w
>vNE3S_
K pmq C$
public synchronized int write(byte[] b,int nStart,int nLen) s2 $w>L
{ 2=X.$&a
int n = -1; t5EYu*
try{ [\=1|t5n~
oSavedFile.write(b,nStart,nLen); }q:4Zh'l!
n = nLen; (1%A@4
} c`7dNx
catch(IOException e) PsN_c[+
{ nsu RG
e.printStackTrace (); JC7:0A^
} H)5"<=]
Oo9'
C%"aj^u
return n; Om2w+yU
} 66scBi_d
~FnY'F<35
;V84Dy#b
} e,l-}=5*P
i_p-|I:hQ
a!,X@5
/* n{"a0O
**SiteInfoBean.java UFyk%#L
*/ iO}KERfU
package NetFox; 1}OM"V
*4c5b'u
=lx~tSiS
public class SiteInfoBean { c4}|a1R\=
6Z{(.'Be
>&Y\g?Z6G
private String sSiteURL; //Site's URL {6>$w/+~
private String sFilePath; //Saved File's Path 0_-P~^A
private String sFileName; //Saved File's Name 'v5q/l
private int nSplitter; //Count of Splited Downloading File B\+uRiD8w
~g*5."-i
;G*)7fi
public SiteInfoBean() ]qiX"<s>~C
{//nSplitter的缺省值为5 F:LrQu
//default value of nSplitter is 5 igF<].'V
this("","","",5); 0*6Q8`I
} FPu$Nd&\
Tj!rAMQk
~F>'+9?Sn
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) fPG3$<Zr
{ h79~d%-
sSiteURL= sURL; h/*@ML+bB8
sFilePath = sPath; 2g;Id.i>
sFileName = sName; i>(TPj|
this.nSplitter = nSpiltter; /b410NP5
1+qP7 3a^
uz;eYD
} &@'+h* b
@GF3g=
a?*pO`<J{
public String getSSiteURL() 3]kN9n{
{ >C`#4e?}
return sSiteURL; Fm+V_.H/;
} %Hu.FS5'
#j"GS/y"
5i%\m
public void setSSiteURL(String value) m1M6N`f
{ 6+:;Mb_S
sSiteURL = value; 593!;2/@
} ,Uy;jk
Ei89Ngp\}
3Qu-X\
public String getSFilePath() T[2<_nn=
{ sk@aOv'*(
return sFilePath; T75N0/teS
} 4K,S5^`Gx
m,ur{B8 :
M%7|7V<o)^
public void setSFilePath(String value) AsI.8"
{ JI/iq
sFilePath = value; 6#HnA"I2n
} 3!i{4/
{"db1Gbfg
kA9k^uR/
public String getSFileName() w7f)v\p
{ 2%)~E50U
return sFileName; @)@tIhw
} ){KrBaGa4
o Va[
bl\;*.s'
public void setSFileName(String value) :bXTV?#0
{ t|*UlTLm
sFileName = value; im F,8'
} X,D ]S@
w{GEWD{&
kB=5=#s
public int getNSplitter() D[{"]=-
{ VREDVLQT
return nSplitter; olK*uD'`
} >S%}HSPKq
<}F(G-kV6
)M8@|~~
public void setNSplitter(int nCount) zo@,>'m
{ gBZNO! a,d
nSplitter = nCount; .I%B$eH
} f4vdJ5pV
} Hro)m"
4G RHvA.
/bmkt@$-0
/* Sp]ov:]%f
**Utility.java Y@+9Ukd/
*/ [YJ*zO
package NetFox; u\km_e
U@:l~xJ
OK2\2&G
public class Utility { hPUZ{#;n
?"@SxM~\
P@Vs\wAT
public Utility() *Zn,v-d
{ "@rHGxK
".?y!VY
\U'*B}Sz
} u(JuU/U
7<k@{xI/
//线程睡眠 !>Q{co'
public static void sleep(int nSecond) D2zqDo<+;
{ wd1>L) T
try{ SRrp=>w?
Thread.sleep(nSecond); nWUau:%
} epcvwM/A
catch(Exception e) P#"_H}qC*
{ T7N\b]?j@Y
e.printStackTrace (); +y][s{A
} Se(apQH
} &+GbklUB~
Z1wfy\9c8
//日志 ;XXEvRk
public static void log(String sMsg) Uh^j;s\y
{ WL3J>S_
System.err.println(sMsg); Y>K8^GS
} rK4 pYo
?S.LGc
~xc0Ky?8
public static void log(int sMsg) Kc+9n%sp
{ 5"D\n B%
System.err.println(sMsg); Ah zV?6e
} f?"909&
} fLV@~T|
][~rk?YY
|^#Z!Hp_Y
/* 5e2yJ R
**TestMethod.java )7Oj
*/ Z*'_/Grv?
package NetFox; z0T6a15f!P
qnO/4\qq
5'EoB^`8N~
public class TestMethod { yaAg!mW
jjg&C9w T
w# ;t$qz}
public TestMethod() l!IN#|{(
{ ///xx/weblogic60b2_win.exe Ub[UB%(T
try{ OO;I^`Yn
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); o^u}(wZ{
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); =E&1e;_xlE
SiteFileFetch fileFetch = new SiteFileFetch(bean); e(9K.3@{
fileFetch.start(); e{.P2rnh
} xP 3>8Y
catch(Exception e){e.printStackTrace ();} (dym*_J
^L'<%_#.
u#0EZ2>#
} j0S[JpoF
ZOL#Q+U
A$TFa:O|
public static void main(String[] args) ;\iu*1>Z,&
{ _ sBFs.o
new TestMethod(); D~,iI7ac
} TH+TcYqO
} CDDEWVd
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