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)); Y}R$RDRL
} !i-t6f
for(int i=0;i<nEndPos.length-1;i++) $|g1 _;(G
{ !@Qk=Xkg
nEndPos = nStartPos[i+1]; uc+{<E3,%
} kQbZ!yl>[
nEndPos[nEndPos.length-1] = nFileLength; 082iEG
} .%n_{ab1
} nC,QvV
7P3pjgh
/5Qh*.(S
//启动子线程 W !j-/ql
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; n-8/CBEH(
for(int i=0;i<nStartPos.length;i++) @ywtL8"1~
{ %Ve@DF8G
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), (K=0c6M3=
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), #[9UCX^=
nStartPos,nEndPos,i); 6k;5T
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); VnW6$W?g
fileSplitterFetch.start(); WRu(F54Sk
} :'F,l:
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), f> Jj5he/
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); h+B7BjA>G
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", xwZ1Q,'C
nEndPos = " + nFileLength); !Q|aR
// fileSplitterFetch[nPos.length-1].start(); 7<]&pSt=
w>f.@luO4
$7AsMlq[(
//等待子线程结束 1 jB0gNe
//int count = 0; 3@x[M?$
//是否结束while循环 4dFr~ {
boolean breakWhile = false; =JE<oVP8
]pe7I P
TM6wjHFm
while(!bStop) m]U
{ 1(Vv-bq$
write_nPos(); QDYuJ&!h
Utility.sleep(500); j%` C
breakWhile = true; s:6K'*
j7&#R+f
yT OZa-
for(int i=0;i<nStartPos.length;i++) DI8I'c-P
{ l=XZBe*[g'
if(!fileSplitterFetch.bDownOver) m33&obSP
{ |GQq:MB;z
breakWhile = false; ru`7iqcz
break; Fu{VO~w
} bX38=.up
} yWZ_
if(breakWhile) 7#"NKxb
break; Y S7lB
U3Gg:onuE
46T(1_Xt~
//count++; {91Y;p C
//if(count>4) o0No"8DnjH
// siteStop(); fIpS P@$<
} (^B1Kt!<
STu(I\9
`/m]K~~
System.err.println("文件下载结束！"); -ABj>y[
} /xgC`]-
catch(Exception e){e.printStackTrace ();} D#'CRJh;7
} )OQm,5F1
4IZAJqw(*
^~l@ _r
//获得文件长度 (BH<\&yHE
public long getFileSize() 9-j-nx @)
{ ]EF"QLNN(
int nFileLength = -1; :fRta[
try{ uYs45 G
URL url = new URL(siteInfoBean.getSSiteURL()); 8?L-3/
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); BPW.&2?<
httpConnection.setRequestProperty("User-Agent","NetFox"); tC1'IE-h
p?Ux1S
T)22P<M8
int responseCode=httpConnection.getResponseCode(); ~,s'-
if(responseCode>=400) tAjT-CXg
{ !4^Lv{1QZ
processErrorCode(responseCode); lu>G=uCJ
return -2; //-2 represent access is error 7C2Xy>d~
} -+qg
|a[" ^ 2
>nehyo:#
String sHeader; JK{2hr_a
y<IHZq`C3
2PPb
for(int i=1;;i++) c9uu4%KG6<
{ LmsPS.It
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); p{qA%D
//Utility.log(in.readLine()); Z{ YuX
sHeader=httpConnection.getHeaderFieldKey(i); b[&ri:AC
if(sHeader!=null) -*&aE~Cs
{ _,F\%}
if(sHeader.equals("Content-Length")) HIj:?y
{ Y -BZV |
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); 7Fa<m]k
break; h+q#|N
} B2BG*xa
} pIm ]WNX(
else ~nj+"d]
break; Eos;7$u[
} ='Oxy
} =RWY0|f
catch(IOException e){e.printStackTrace ();} 9l&G2o
catch(Exception e){e.printStackTrace ();} fe6Op
_Co v>6_i
}]=A:*jD
Utility.log(nFileLength); l)KN5V
"AWk jdj
Pa; *%7
return nFileLength; kd p*6ynD
} "$"<AKCwS
L^s?EqLXS
URh5ajoR%
//保存下载信息（文件指针位置） f4X}F|!h
private void write_nPos() S]&i<V1qX
{ N'5DB[:c:
try{ su-0G?c
output = new DataOutputStream(new FileOutputStream(tmpFile)); (d <pxx
output.writeInt(nStartPos.length); f|!@H><
for(int i=0;i<nStartPos.length;i++) hL;??h,!_
{ !P6y_Frpe
// output.writeLong(nPos); !C.{nOfyv
output.writeLong(fileSplitterFetch.nStartPos); FzBny[F
output.writeLong(fileSplitterFetch.nEndPos); dt>!=<|k
} b` 9Zin
output.close(); {#{nU NW
} D{t0OvQag
catch(IOException e){e.printStackTrace ();} 5kv]k?
catch(Exception e){e.printStackTrace ();} xJvalb
} i079 V
52 DSKL
Y}x_ud,
//读取保存的下载信息（文件指针位置） WN#dR~>
private void read_nPos() ZQJh5.B
{ ~1{~iB2G
try{ h/l?,7KHI
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); Lhgs|*M
int nCount = input.readInt(); #|e5i9l*B
nStartPos = new long[nCount]; 3'`X_C|d53
nEndPos = new long[nCount]; u-dF~.x
for(int i=0;i<nStartPos.length;i++) c$3ZEe
{ yD ur9Qd6
nStartPos = input.readLong(); o\yqf:V8
nEndPos = input.readLong(); (b1rd
} N<lf,zGw
input.close(); L\kT9wWK|
} 0k|/]zfb
catch(IOException e){e.printStackTrace ();} l_=kW!l
catch(Exception e){e.printStackTrace ();} jM(!!AjpC
} ^m^,:]I0P
M Xl!
7m9T'
private void processErrorCode(int nErrorCode) ]GHx<5Q:\
{ hB*3Py27L
System.err.println("Error Code : " + nErrorCode); }(if|skau
} CQ%yki
*FoPs
=}4lx^`oeT
//停止文件下载 AqP\g k
public void siteStop() OBp/:]
{ ~f%AbDye
bStop = true; e?b<-rL
for(int i=0;i<nStartPos.length;i++) d`Em)3v
fileSplitterFetch.splitterStop(); ol8uV{:"
iJK rNRj
SxCzI$SGu
} gIXc-=Ut
} z15QFVm
//负责部分文件的抓取 [ w1"
**FileSplitterFetch.java rO{"jJ
*/ 5B=Wnau
package NetFox; F1o"H/:n
c)o[3o7
5Bc)QKh`l|
import java.io.*; }GTy{Y*&
import java.net.*; u~d&<_Z
4.mbW
QCWk[Gx
public class FileSplitterFetch extends Thread { T)B1V,2j=
S$I:rbc
Mky8qVQ2
String sURL; //File URL >(HUW^T/9z
long nStartPos; //File Snippet Start Position XUT\nN-N
long nEndPos; //File Snippet End Position {*CLWs4
int nThreadID; //Thread's ID &^YY>]1Py
boolean bDownOver = false; //Downing is over /`Lki>"
boolean bStop = false; //Stop identical 7u^6`P
FileAccessI fileAccessI = null; //File Access interface jQ31u
1P\_3.V{
bqg\V8h
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException d|sI>6jD
{ |Y1<P^
this.sURL = sURL; <cz~q=%v2&
this.nStartPos = nStart; uL4@e
this.nEndPos = nEnd; c$'UfW
nThreadID = id; X|wXTecg*|
fileAccessI = new FileAccessI(sName,nStartPos);//定位 Cst>'g-yB
} Z@8amT;Y
zj;y`ENj
wEMUr0Hq
public void run() GOwd=]e
{ [P{Xg:0
while(nStartPos < nEndPos && !bStop) 6C/D&+4
{ t5N4d
WiviH#hF
ix&hsNzD
try{ ;o3 .<"
URL url = new URL(sURL); ^HL#)fK2I
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); ~ab"q%
httpConnection.setRequestProperty("User-Agent","NetFox"); tY:-13F
String sProperty = "bytes="+nStartPos+"-"; <ZrZSt+<
httpConnection.setRequestProperty("RANGE",sProperty); ^?xXP=/
Utility.log(sProperty); g%=\Wiit]
qW<: `y
D1O7S]j
InputStream input = httpConnection.getInputStream(); +dh]k=6
//logResponseHead(httpConnection); |#2<4sd
Ruk6+U
h=4{.EegG&
byte[] b = new byte[1024]; xG}eiUbM`
int nRead; sX_^H%fd
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) ;.:UfW
{ .(1$Q6yG
nStartPos += fileAccessI.write(b,0,nRead); JrL/LGY
//if(nThreadID == 1) a*IJ)'S
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); >LU*F|F]B
} kkOYC?zE?
P7y[9|^
mc$c!Ax*
Utility.log("Thread " + nThreadID + " is over!"); aQ~x$T|
bDownOver = true; xZhD6'Zzz
//nPos = fileAccessI.write (b,0,nRead); [7s5Vt|
} mifYk>J^9
catch(Exception e){e.printStackTrace ();} (wY%$kW4
} MK[spV
} f@/qW!o
&'](T9kg=
[a |fm*B!
//打印回应的头信息 <?J7Z|
public void logResponseHead(HttpURLConnection con) u('OHPqq
{ TwhK>HN
for(int i=1;;i++) m5x>._7le
{ *HXq`B
String header=con.getHeaderFieldKey(i); lb6s3b
if(header!=null) %!$-N!e
//responseHeaders.put(header,httpConnection.getHeaderField(header)); slmxit
Utility.log(header+" : "+con.getHeaderField(header)); !KlSw,&=.6
else 1aDDl-8,
break; ^#Y6 E
} V_1#7
} `x#~-
-*Pt781
SBoF(0<
public void splitterStop() [:=[QlvV
{ AP7W)S
bStop = true; eJA{]^Zf
} (hV"z;rI
bYgYP|@
ppD~xg]
} 3"hR:'ts
zn x_p/V
W.R'2R#
/* R _Y&Y-
**FileAccess.java $"(YE #]|
*//文件访问(定位，写) dtBV0$
package NetFox; !491 \W0ZH
import java.io.*; Mfr#IzNHN
c+{4C3z
JT9<kB/07
public class FileAccessI implements Serializable{ kC5,yj
S}f<@-16P
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 Ft rw3OxN
RandomAccessFile oSavedFile; FlG^'UD
long nPos; 2ML6Lkk
Rx"Qwi,\U
R"o,m
public FileAccessI() throws IOException Lp WEu^j
{ "6.p=te
this("",0); a0.3$
} wg.fo:Q
Ve1] ECk
E<SEFn
public FileAccessI(String sName,long nPos) throws IOException q$rA-`jw
{ \>`$x:
oSavedFile = new RandomAccessFile(sName,"rw"); 0Ida]H
this.nPos = nPos; o#) !b:/
oSavedFile.seek(nPos); ZcRm5Du~:
} $)]FCuv
f4T0Y["QA
walRqlo@
public synchronized int write(byte[] b,int nStart,int nLen) kte.E%.PE
{ "BfmX0&?
int n = -1; mZVOf~9E
try{ UjOhaj "h
oSavedFile.write(b,nStart,nLen); m=,c,*>
n = nLen; l1Q+hz5"*U
} PB67?d~
catch(IOException e) 7U`S9DDwq
{ ^!F5Cz 48
e.printStackTrace (); -+>r4P
} ^p zxwt
Q]5^Eiq8
&E riskI
return n; PZ(<eJ>
} arQ%
lO:{tV
G=5t5[KC
} K[gWXBP
kz;_f
kok^4VV
/* "5JNXo,H
**SiteInfoBean.java kF,\bM
*/ 6Hbf9,vI
package NetFox; ZHF(q6T
L##8+OJ.L
niHL/\7u
public class SiteInfoBean { _d| 62VS
u1{ym_
5J+V:Xu{
private String sSiteURL; //Site's URL .e2A*9,
private String sFilePath; //Saved File's Path /Ej]X`F
private String sFileName; //Saved File's Name -+=:+LhSMb
private int nSplitter; //Count of Splited Downloading File M1^C8cz
^_KD&%M6
~d%;~_n
public SiteInfoBean() %|(?!w7
{//nSplitter的缺省值为5 "8muMa8Q%
//default value of nSplitter is 5 !UMo4}Y
this("","","",5); yD"0=\
} \;*}zX
}S vw,c
<@e+-$
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) Xs>s|_T
{ .K@x4 /1
sSiteURL= sURL; +:,`sdv6o
sFilePath = sPath; +|?|8"Qg
sFileName = sName; mheU#&|
this.nSplitter = nSpiltter; R@<_Hb;Aeb
=`1m-
<m>l-]
} mUt,Z^ l`
>WGP{
:G`L3E&1s
public String getSSiteURL() \+{t4Im
{ o3F|#op
return sSiteURL; ~n/Aq*
} ~y)bYG!G
%K^gUd>,R
fQQsb 5=i
public void setSSiteURL(String value) p/hvQyE
{ kG$E tE#
sSiteURL = value; %'"HGZn b
} wHtJ_Y
Q=(@K4
&"[)s[m+t
public String getSFilePath() g8I!E$
{ "]T$\PJun
return sFilePath; 7$ =Y\P
} 4bi NGl~
0iJ!K;A2%
^qeY9O
public void setSFilePath(String value) 3I"NI.>*
{ 6 u-$
sFilePath = value; !/j,hO4Z4
} ?< cM^$lI>
/2;dH]o0
GIm " )}W
public String getSFileName() MzQ\rg_B7
{ c~}={4M]
return sFileName; SyK9Is{8
} OM.k?1%+M
XXW]0{k:y
-AjH}A[!
public void setSFileName(String value) bLgL0}=n
{ *u>lx!g
sFileName = value; H8@8MFz\
} :dP~.ZY7
}* QO]_U?
ZFS7{:
public int getNSplitter() $. %L
{ 7}be>(
return nSplitter; AF^T~?t
} .'|mY$U~]
XTJvV
EM=w?T
public void setNSplitter(int nCount) "8N"Udu
{ OAv>g pw
nSplitter = nCount; kdp% !S%2
} OJAx:&]3
} v`JF\"}S
RMoJz6^>
q-3]jHChh
/* b~7Jh:%@;
**Utility.java ^q ;Cx7T_p
*/ 5m4DS:&
package NetFox; ~eP
9tn;L"#&N
9)`amhf>
public class Utility { gv#4#]
]q{ PDZ
x?"#gK`3;
public Utility() {<2>6 _z
{ =SAV|
o(*F])d;
ZK6Hvc0
} mOP4z'
#^6^
//线程睡眠 <l$P&jSF3
public static void sleep(int nSecond) 740B\pc0
{ Yi(1^'Bi
try{ =m7H)z)i*J
Thread.sleep(nSecond); fc@'9-pt
} j!\dn!Xwt
catch(Exception e) zB*euHIqZ
{ xRum*}|4
e.printStackTrace (); F8<"AI
} s)zJT
} =E(#YCx
h >-'-Hx+
//日志 ACg;CTBb
public static void log(String sMsg) AF}gSNX
{ VO=!8Yx[
System.err.println(sMsg); yto[8;)_
} Q&CElx?L
.oqIZ\iik
1l5JP|x
public static void log(int sMsg) 5\bJR0I@
{ 6)qp*P$L
System.err.println(sMsg); dRW$T5dac
} d(-EcY>?
} UMU2^$\iS
.5w azvA
!E2W\chi
/* (YPi&w~S
**TestMethod.java k()$:-V
*/ zF`3gl.
package NetFox; u5B:^.:p
7b[wu~'( n
8`=v.
public class TestMethod { 8R/dA<Ww
E5</h"1
a0=WfeT
public TestMethod() cA)[XpQ:+W
{ ///xx/weblogic60b2_win.exe GbI-SbE
try{ d\]Yk]r
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); 6gH{R$7L=
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); W$0^(FH[
SiteFileFetch fileFetch = new SiteFileFetch(bean); :e<7d8E5n{
fileFetch.start(); [sF(#Y:I
} cPDQ1qre!
catch(Exception e){e.printStackTrace ();} cxIk<&i~(
pO7Zs
v{aq`uH
} -VxDNT}Tr
bD^b
A9BX_9}]
public static void main(String[] args) 0@I S
{ zCv"]%
new TestMethod(); 3"N)xO-
} 7aV%=_
} ,:LA.o}h
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