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)); nKr9#JebRC
} }G<T:(a
for(int i=0;i<nEndPos.length-1;i++) 3riw1r;Q
{ F^$led1/F
nEndPos = nStartPos[i+1]; QnouBrhO
} 'J)2g"T@
nEndPos[nEndPos.length-1] = nFileLength; VhGs/5
} ?L) !pP]
} 1nknSw#
P,S G.EFK
Flxvhl)L
//启动子线程 ,B}I?vN.
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; RC#C\S6
for(int i=0;i<nStartPos.length;i++) L)QE`24
{ #L}+H!Myh
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), Uggw-sRU
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), CWo1.pVw
nStartPos,nEndPos,i); .9[45][FK
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); H5cV5E0
fileSplitterFetch.start(); r\6"5cQ=
} w2O!M!1
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), A=zPLq{Sb
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); g.JN_t5
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", /.Nov
nEndPos = " + nFileLength); gwd (N
// fileSplitterFetch[nPos.length-1].start(); d@0Kr5_
`i +g{kE2M
5qUTMT['T
//等待子线程结束 hJz):d>Im
//int count = 0; cV{%^0?D
//是否结束while循环 [L$9p@I
boolean breakWhile = false; "&Dx=Yf
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I:V0Xxz5t
while(!bStop) R #]jSiS
{ ,5Pl\keY
write_nPos(); Nr<`Z
Utility.sleep(500); JPM))4YDR
breakWhile = true; ]{~NO{0@Y
; |/leu8
;< )~Y-
for(int i=0;i<nStartPos.length;i++) kU-t7'?4
{ ,vqr<H9e
if(!fileSplitterFetch.bDownOver) Rv,JU6>i
{ (R~]|?:wt
breakWhile = false; if;71ZE
break; ./j,Z$|
} 9z;HsUv
} <!$:8ls
if(breakWhile) "N:XzG
break; 0n~Zz
<WXzh5D2
@pI5lh
//count++; x6afI<dm
//if(count>4) zOEY6lAwI
// siteStop(); &bz:K8c
} `u!l3VZ/4
@UBjq%z
GT hL/M
System.err.println("文件下载结束！"); M}_i52
} .O*bILU
catch(Exception e){e.printStackTrace ();} 2-zT$`[]J
} 5 )2:stT73
v]%WH~>
b5IA"w
//获得文件长度 6ZgU"!|r
public long getFileSize() fW`&'!
{ OX%MP!#KU
int nFileLength = -1; FG3UZVUg9
try{ A`}yBSb
URL url = new URL(siteInfoBean.getSSiteURL()); w#JJXXQI
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); /MB{Pmk$R
httpConnection.setRequestProperty("User-Agent","NetFox"); ; UiwH
%;D+k
3'c\;1lhT
int responseCode=httpConnection.getResponseCode(); biozZ
if(responseCode>=400) Iu~\L0R427
{ FLoNE>q
processErrorCode(responseCode); 4$/i%B#ad
return -2; //-2 represent access is error =.|J!x
} e&MC|US=\
1[*UYcD
,U)"WLmY
String sHeader; mD:IO
(vR 9H(#
4RKW
for(int i=1;;i++) UgB'[@McS
{ _46X%k
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); Z'^U ad6
//Utility.log(in.readLine()); iFSJL,QZ3
sHeader=httpConnection.getHeaderFieldKey(i); =O _z(
if(sHeader!=null) e98lhu"|H
{ Md)zEj`\
if(sHeader.equals("Content-Length")) ~,D@8tv
{ =k3!RW'
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); CV$],BM
break; ej&<GM|
} U%7i=Z{^Ks
} gIR^)m
else h@7FY
break; JB</euyV
} sUl6hX4
} E'1+Yq
catch(IOException e){e.printStackTrace ();} k&#a\OJ7u
catch(Exception e){e.printStackTrace ();} ]U[X1W+@
:J}t&t
\&V0vN1
Utility.log(nFileLength); -]Cc
Xf=XBoN|
_FbC{yI8;
return nFileLength; HQ9f,<
} s/"&9F3
qP!eJ6[Nh"
*IlaM'[*
//保存下载信息（文件指针位置） w)E@*h<Z
private void write_nPos() [MX;,%;;
{ `&M{cfp_
try{ C8@TZ[w
output = new DataOutputStream(new FileOutputStream(tmpFile)); /|{,sWf2
output.writeInt(nStartPos.length); 6 y"-I!&
for(int i=0;i<nStartPos.length;i++) +&tgJ07A
{ Y9SGRV(
// output.writeLong(nPos); Uts"aQ
output.writeLong(fileSplitterFetch.nStartPos); B;Nl~Y|\
output.writeLong(fileSplitterFetch.nEndPos); #LcrI
} K.tlo^#^B[
output.close(); ||2Q~*:
} J2GcBzRH
catch(IOException e){e.printStackTrace ();} hovGQHg
catch(Exception e){e.printStackTrace ();} 5yh/0i5|
} zHB_{(o7
-0o[f53}p
t^=U*~
//读取保存的下载信息（文件指针位置） XA0(f*
private void read_nPos() 9D@$i<D:
{ BUUf;Vv
try{ 6XEZ4QP}
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); 9z m|Lbj
int nCount = input.readInt(); D|I Ec?
nStartPos = new long[nCount]; @mw "W{
nEndPos = new long[nCount]; {hSGv
for(int i=0;i<nStartPos.length;i++) kg5ev8
{ NCeaL-y7
nStartPos = input.readLong(); 4}v@C|.p
nEndPos = input.readLong(); CDMfa&;T
} [c K^+s)N
input.close(); ske@uzAz
} jdut4 nFc
catch(IOException e){e.printStackTrace ();} &Y|Xd4:
catch(Exception e){e.printStackTrace ();} L/}iy}
} $*MCUnl
@`u?bnx]e
TDK@)mP
private void processErrorCode(int nErrorCode) ZU'!iU|8
{ H(+<)qH
System.err.println("Error Code : " + nErrorCode); \L!uHAE2a
} 3EFD%9n
n/e BE q
U0B2WmT~Q
//停止文件下载 `hh9"Ws%
public void siteStop() ?dy~mob
{ W+>wu%[L
bStop = true; aA*9,
for(int i=0;i<nStartPos.length;i++) ucYkxi`x
fileSplitterFetch.splitterStop(); hAR? t5c
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Bl.u=I:Y4
} Ayx^Wp*s
} I8m:3fL"
//负责部分文件的抓取 #mc!Wt10
**FileSplitterFetch.java *DeTqO65
*/ <dR,'
package NetFox; :{g7lTM
B:oF;~d/,
tn<6:@T
import java.io.*; :Z`4j
import java.net.*; W*T{,M@Y
"X1vZwK8N
zok D:c
public class FileSplitterFetch extends Thread { $%qg"
gtU1'p"
*_hLD5K!
String sURL; //File URL T{MC-j _T9
long nStartPos; //File Snippet Start Position W?,$!]0
long nEndPos; //File Snippet End Position D5]{2z}k
int nThreadID; //Thread's ID 6vz1*\:H~
boolean bDownOver = false; //Downing is over m@qqVRn#)
boolean bStop = false; //Stop identical Agy <j
FileAccessI fileAccessI = null; //File Access interface D&{ *AH%Q
<)#kq1b?
," R>}kPli
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException O]=C#E{
{ o"_=K%9
this.sURL = sURL; u}jrfKdE
this.nStartPos = nStart; +$pJ5+v
this.nEndPos = nEnd; (!zM\sF
nThreadID = id; 9U<Hf32
fileAccessI = new FileAccessI(sName,nStartPos);//定位 F>Jg~ FD*
} QlzQ]:dWC
M []OHw
vjK, I9
public void run() p5*lEz|$
{ n6f3H\/P&
while(nStartPos < nEndPos && !bStop) |-kEGLH[*V
{ ?SX_gYe9
(K #A
h5onRa*7
try{ )!-S|s'
URL url = new URL(sURL); z+"0>ZN&
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); c^S&F9/U*
httpConnection.setRequestProperty("User-Agent","NetFox"); :XS"#^aJ
String sProperty = "bytes="+nStartPos+"-"; ,P@QxnQ
httpConnection.setRequestProperty("RANGE",sProperty); gMZ&,n4
Utility.log(sProperty); 8XbR
79tJV
1q!sKoJ<
InputStream input = httpConnection.getInputStream(); N(R,8GF5G
//logResponseHead(httpConnection); lG]GlgSs
Nmf#`+7gCI
NgxO&Zp
byte[] b = new byte[1024]; \{>eOD_
int nRead; FOp_[rR
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) MVAc8dS
{ dofR)"<p,^
nStartPos += fileAccessI.write(b,0,nRead); z(UX't (q
//if(nThreadID == 1) r5)f82pQ
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); rk|a'&
} 0*{p Oe/u
R6Pz#`n
w:R]!e_6\9
Utility.log("Thread " + nThreadID + " is over!"); & =sayP
bDownOver = true; ~%GSsm\J
//nPos = fileAccessI.write (b,0,nRead); m?vAyi
} f[M"EMy
catch(Exception e){e.printStackTrace ();} gT7I9 (x!W
} !L$oAqW
} "GBUQ}
7eH@n<]Y2
*EE|?vn
//打印回应的头信息 ke</x+\F
public void logResponseHead(HttpURLConnection con) %>NRna
{ ZArf;&8
for(int i=1;;i++) Oi#k:vq4
{ s @3zx
String header=con.getHeaderFieldKey(i); JgZdS-~
if(header!=null) rN'k4V"K
//responseHeaders.put(header,httpConnection.getHeaderField(header)); a!{hC)d*
Utility.log(header+" : "+con.getHeaderField(header)); CY\mU_.b
else h@/>?Va
break; W.sD2f
} p!V)55J*
} ri;r7Y9V9`
IT7:QEfKU
2f /bEpi
public void splitterStop() <#!8?o&i
{ zkvH=wL
bStop = true; 6UtG-WHHt
} ]n/jJ_[
yl|R:/2V
9Z}S]-u/
} ;+!xZOmm
DwQp$l'NfW
(jt*u (C&Y
/* l$qmn$Uc
**FileAccess.java \>_eEZ5
*//文件访问(定位，写) LIc*tsl
package NetFox; + >Fv*lux
import java.io.*; jh-kCF
HM;4=%
puk4D
public class FileAccessI implements Serializable{ ([E#zrz%
P'KY.TjWb
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 !$4Q]@ }
RandomAccessFile oSavedFile; 1"N/ZKF-x
long nPos; iOE9FW|e
s"gKonwI2
F\I5fNs@
public FileAccessI() throws IOException 3BuD/bs
{ * ,|)~$=>
this("",0); zV9 =
} B>c[Zg1
>IR`]
]M02>=1
public FileAccessI(String sName,long nPos) throws IOException xow6@M,
{ 9}IVNZc
oSavedFile = new RandomAccessFile(sName,"rw"); OD>u$tI9
this.nPos = nPos; n/,rn>k7:
oSavedFile.seek(nPos); N GX-'w
} 3g4vpKg6c
~`a#h#
=+kvL2nx-
public synchronized int write(byte[] b,int nStart,int nLen) j=zU7wz)D
{ 0YgFjd 5
int n = -1; %`8KG(F^
try{ il 8A&`%
oSavedFile.write(b,nStart,nLen); 7cJO)cm0'
n = nLen; T=iZ9w
} fbW,0
catch(IOException e) hv_pb#1Ks
{ Lk$Je O
e.printStackTrace (); wt3Z?Pb
} bF8xQ<i~Y
t/EMBfLc
M,=@|U/B
return n; k1@ A'n
} "m<eHz]D
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} 8=u+BDG
bHlDm~5
7J</7\
/* _tWfb}6;Zb
**SiteInfoBean.java T5X'D(\|
*/ R-0_226
package NetFox; ~ L i%
0YTtA]|`4
av|6r#
public class SiteInfoBean { d%[`=fs]|m
E?;T:7.%
F"HI>t)>
private String sSiteURL; //Site's URL Ot8S'cB1,$
private String sFilePath; //Saved File's Path %RK\Hz2q3
private String sFileName; //Saved File's Name EY[Q%
private int nSplitter; //Count of Splited Downloading File Q,`2DHhK
\p=W4W/
7T(OV<q;#
public SiteInfoBean() c<t3y7
{//nSplitter的缺省值为5 r>:7${pF
//default value of nSplitter is 5 r&l*.C*
this("","","",5); (w@MlMk
} &j~|3
+8@`lDnr
"3KSmb
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) TF iM[
{ )DZ-vnZ#t0
sSiteURL= sURL; ?U9d3] W
sFilePath = sPath; XCi]()TZ_
sFileName = sName; ?M{6U[?
this.nSplitter = nSpiltter; [E :`jY
S&)) 0d
>a`zkl
} GO GXM4I
!O-_Dp\#
+K?N:w
public String getSSiteURL() "VVR#H}{
{ SAo\H
return sSiteURL; LkZo/K~
} UE$[;Zg
<W[8k-yOV`
a]=vq(N'r
public void setSSiteURL(String value) P+%)0*W
{ "drh+oo.
sSiteURL = value; 8JOht(m
} SUi1*S
/B?SaKh
/zP)2q^
public String getSFilePath() po$ynp756
{ SoGLsO+R
return sFilePath; hv8[_p`>
} EKS<s82hF&
.yh2ttf<gB
96E7hp !:
public void setSFilePath(String value) 3%4Mq6Q`
{ T]Td4T!
sFilePath = value; a.U:B [v`
} h/bYtE
gsq[ 9
h _7;UQH
public String getSFileName() y!c7y]9__2
{ l \n:"*To
return sFileName; e^Wv*OD'
} Olh%"=*;
#_L&
E=~WQ13Q
public void setSFileName(String value) dv}R]f'
{ jL).B&
sFileName = value; k<";t
} Z q>.;>
2DqHqq9m
R M+K":p
public int getNSplitter() kJpHhAn4
{ QAnfxt6
return nSplitter; iKH T
} QNa3S*
k)' z<EL6c
;9 n8on\
public void setNSplitter(int nCount) ssbyvzQ
{ moI<b\G@
nSplitter = nCount; ^M5uLm-_s
} H0NyxG<
} M@[gT?mv1
*G|]5
kV9NFo22
/* J|8YB3K,
**Utility.java yVv3S[J
*/ ):EXh#
package NetFox; 7+r5?h|
YVp0}m
!7*/lG
public class Utility { RtQfE+
boB{Y7gO4
JY8pV+q @=
public Utility() RA67w&
{ ${eh52)`
TL:RB)- <
#T`+~tW'|
} 640V&<+v
)`7h,w J[1
//线程睡眠 M<pgaB0
public static void sleep(int nSecond) FEswNB(]*
{ ~,7R*71
try{ }}R!Y)
Thread.sleep(nSecond); ..mz!:Zs0
} bZfJG^3
catch(Exception e) >9|+F[Fc
{ +c_CYkHJ/
e.printStackTrace (); $>m<+nai'
} a8c]B/
} K#m o+n5-;
El}z^e
//日志 Xxw.{2Ji!q
public static void log(String sMsg) AOUO',v
{ #oY7v,x\
System.err.println(sMsg); .1}(Bywm5
} U%l{>*q
wyM3|%RZ
n_glYSV!
public static void log(int sMsg) ]h@:Y]
{ Q)&Ztw<
System.err.println(sMsg); Y [S^&pF
} TUr}p aw_
} R5zV=N
1]~}0;,
=h{2!Ah7 X
/* KQ3 On(d
**TestMethod.java \3/'#
*/ SYx)!n6U
package NetFox; TmiQq'm[b
mH"`46
Ja1*a,],L
public class TestMethod { =|/b[Gd(
P2kZi=0
1;V5b+b
public TestMethod() nFSa~M
{ ///xx/weblogic60b2_win.exe &\r%&IX/
try{ cAS5&T<
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); 3ssio-X
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); P.0-(
SiteFileFetch fileFetch = new SiteFileFetch(bean); .wywO|
fileFetch.start(); WjB[e>
} sh1fz 6g
catch(Exception e){e.printStackTrace ();} Oc>-jhx?
NINiX(
Bv3v;^
} JQqDUd
ia[wVxd
yLP0w^Q
public static void main(String[] args) Zl)|x%z
{ ~+F: QrXcI
new TestMethod(); %j,Ny}a
} '"EOLr\Z,
} /zWWUl`:
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