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)); *WdnP.'Y
} n`gW&5,,z
for(int i=0;i<nEndPos.length-1;i++) VN6h:-&iY
{ +AkAMZ"Mg
nEndPos = nStartPos[i+1]; 1(t{)Z<
} P7np -I*
nEndPos[nEndPos.length-1] = nFileLength; qp$Td<'Y
} 8WU_d`DF
} t)o!OEnE
TK^9!3
uU_lC5A|
//启动子线程 w6FtDl$
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; 4UP#~
for(int i=0;i<nStartPos.length;i++) 1~rZka[s
{ K;j}qJvsb
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), sg0HYb%_E
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), &(&5ao)5
nStartPos,nEndPos,i); >F7v'-*{
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); rUgTJx&ds
fileSplitterFetch.start(); kD1[6cJ!=.
} Z ,4G'[d
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), %z1y3I|`[t
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); wP:ab
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", /DLgE7iU%
nEndPos = " + nFileLength); EhJpJb[Z
// fileSplitterFetch[nPos.length-1].start(); BhFyEY(
h|m>JDxn
V% -wZL/
//等待子线程结束 IbV 7}
//int count = 0; SA3!a.*c
//是否结束while循环 !.\-l2f
boolean breakWhile = false; .zDm{_'
Vm6 0aXm_
]CLt Km
while(!bStop) xi3
{ )Pj8{.t4
write_nPos(); iH&BhbRu_
Utility.sleep(500); P[q`{TdV
breakWhile = true; L`"B;a&
d9bc>5%-F
EGD&/%aC
for(int i=0;i<nStartPos.length;i++) U_\3preF
{ qC|$0
if(!fileSplitterFetch.bDownOver) *(c><N
{ P`ZYm
breakWhile = false; zI$24L9*
break; v7Q=
} y&F0IJ|`@M
} s01W_P.@R
if(breakWhile) e3YdHp
break; s"jNS1B
)cF1?2
'5V#sq;Z
//count++; =A yDVWpE
//if(count>4) Z#Q)a;RA
// siteStop(); >wPMJ> 2
} iD/r8_}
Adyv>T9
$d[ -feU
System.err.println("文件下载结束！"); Gd=l{~
} >%PPp.R
catch(Exception e){e.printStackTrace ();} ?:8wDV
} OI0tgkG
LEM^8G]O
kVG]zt2
//获得文件长度 _mi(:s(
public long getFileSize() >mWu+Nn:
{ ohy?l
int nFileLength = -1; Vv]81y15Q;
try{ }'o[6#_*X
URL url = new URL(siteInfoBean.getSSiteURL()); #c2InwZV
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); ZJ|@^^GcL
httpConnection.setRequestProperty("User-Agent","NetFox"); Xy;!Q`h(
[u=DAk?8
m{ya%F
int responseCode=httpConnection.getResponseCode(); fUJ\W"qya
if(responseCode>=400) $1(FN+ Mb
{ tG{?
processErrorCode(responseCode); I{V1Le4?
return -2; //-2 represent access is error 1.5lJ:[G
} qL\*rYe<
cuw3}4m%
&dC #nw
String sHeader; s\-^vj3
"eH~/6A
^edg@fp
for(int i=1;;i++) iN}BMd.U
{ l5jW`cl1
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); T21SuM
//Utility.log(in.readLine()); rCmxv7" a}
sHeader=httpConnection.getHeaderFieldKey(i); BBg&ZIYEh
if(sHeader!=null) ;[_w&"[6a
{ 9t$%Tc#Z
if(sHeader.equals("Content-Length")) I)-u)P?2x
{ <IF\;,.c
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); >%"Q]p
break; mndUQN_Gb
} Oc]&1>M
} \E'Nk$V3
else aE_)iE|
break; MRB>(}
} lRn6Zh
} Xcq9*!%o
catch(IOException e){e.printStackTrace ();} [xXml On!
catch(Exception e){e.printStackTrace ();} mX8A XWIa
"~h.u
t;DZ^Z"{
Utility.log(nFileLength); 7eh|5e$@
ifu"e_^
n\2VrUQ)M
return nFileLength; tPS.r.0#^
} YkcX#>,
Sa&~\!0t
O=1uF
//保存下载信息（文件指针位置） }lgqRg)F9[
private void write_nPos() b'$j* N
{ JlsRP
try{ A a2*f[
output = new DataOutputStream(new FileOutputStream(tmpFile)); %J`;
output.writeInt(nStartPos.length); 4/{Io &|
for(int i=0;i<nStartPos.length;i++) j$*]'s&_hZ
{ 'JEZ;9}
// output.writeLong(nPos); +q]
output.writeLong(fileSplitterFetch.nStartPos); VI%879Z\e
output.writeLong(fileSplitterFetch.nEndPos); >GiM?*cC
} z[Kxy1,
output.close(); x5m .MQ J
} ?lb1K'(
catch(IOException e){e.printStackTrace ();} Jkt L|u:k
catch(Exception e){e.printStackTrace ();} I}Z[F,}*J
} z9$x9u
,{c9Lv%@J
1h\:Lj
//读取保存的下载信息（文件指针位置） RR:m<9l
private void read_nPos() }H{{@RU
{ M[_~7~4
try{ 9AJ!7J#v"
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); K0]'v>AWr
int nCount = input.readInt(); 4j!MjlG$
nStartPos = new long[nCount]; dUn8Xqj1
nEndPos = new long[nCount]; `QR2!W70o3
for(int i=0;i<nStartPos.length;i++) 8Es]WR5 ^
{ BzA(yCu$:
nStartPos = input.readLong(); >qx~m>2|8]
nEndPos = input.readLong(); w\_NrsO!x
} .c"UlOZ&w^
input.close(); UL[4sv6\9
} |Xd[%W)
catch(IOException e){e.printStackTrace ();} ~u8}s4
catch(Exception e){e.printStackTrace ();} $X9Ban]
} @DkPJla&
CBSJY&:K
mo#4jtCE
private void processErrorCode(int nErrorCode) ;FZ\PxN
{ Sct-,K%i
System.err.println("Error Code : " + nErrorCode); ru(Xeojv#
} c ~YD|l
{<~XwJ.
p`1d'n[
//停止文件下载 %8$JL=c
public void siteStop() )gR14a
{ uA!T@>vl
bStop = true; 5vbnO]8
for(int i=0;i<nStartPos.length;i++) I2j;9Qcz
fileSplitterFetch.splitterStop(); '[Oi_gE.
=]xNpX)
2WE
} PBn(k>=+
} V.Xz n
//负责部分文件的抓取 8)"KPr63M
**FileSplitterFetch.java ,l; &Tb=k
*/ J-?\,N1R7
package NetFox; dhK$XG
bHS2;K~
)r?i^D&4
import java.io.*; tsfOPth$*
import java.net.*; {k?Y:
).oqlA!
a' #-%!]
public class FileSplitterFetch extends Thread { (m04Z2#
N%r}0
c_ygwO3.Q
String sURL; //File URL n#J$=@
long nStartPos; //File Snippet Start Position Vg \-^$
long nEndPos; //File Snippet End Position ` V^#Sb
int nThreadID; //Thread's ID "mPa>`?
boolean bDownOver = false; //Downing is over RX2= iO"
boolean bStop = false; //Stop identical 3sp*.dk
FileAccessI fileAccessI = null; //File Access interface w,}}mC)\*
$d8A_CUU
)&dhE^ O
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException [0&Lvx
{ C4 Wdt
this.sURL = sURL; r]HLO'<]
this.nStartPos = nStart; y'@l,MN{
this.nEndPos = nEnd; mu{%%b7|^
nThreadID = id; ^w&TTo(
fileAccessI = new FileAccessI(sName,nStartPos);//定位 @{CpC
} t91CxZQ^s
&PgdCijGq;
--^D)n
public void run() 4tuEC-oh
{ .9^;? Ts
while(nStartPos < nEndPos && !bStop) @tj0Ir v
{ jQ^Ib]"K
@nT8[v
6wu/6DO
try{ !k s<VJh
URL url = new URL(sURL); <=7)t.
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); O,OGq0c
httpConnection.setRequestProperty("User-Agent","NetFox"); +;!w;t
String sProperty = "bytes="+nStartPos+"-"; =OHDp7GXO>
httpConnection.setRequestProperty("RANGE",sProperty); %@xYg{
Utility.log(sProperty); F Qk;
n9J>yud|
>{??/fBd-
InputStream input = httpConnection.getInputStream(); zp9 ?Ia
//logResponseHead(httpConnection); EV(/@kN2
7>~iS@7GV
b,`\"'1
byte[] b = new byte[1024]; 4dok/ +Ec
int nRead; MnS"M[y3
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) _0f[.vN
{ Z*QRdB%,
nStartPos += fileAccessI.write(b,0,nRead); y]+A7|
//if(nThreadID == 1) &%bX&;ECzf
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); d{trO;%#f
} <qy+@t
$_ i41f[
lz*2wGI9
Utility.log("Thread " + nThreadID + " is over!"); 8xv\Zj+
bDownOver = true; ~k%\ LZ3s
//nPos = fileAccessI.write (b,0,nRead); \mDm*UuG
} V&nN/CF
catch(Exception e){e.printStackTrace ();} 4HHf3j!5
} l^"G\ZVI
} S-H3UND"
h P1|l
*o#`lH
//打印回应的头信息 19vD(KC<
public void logResponseHead(HttpURLConnection con) Zk[#BUA
{ :h3JDQe:.
for(int i=1;;i++) L!G3u/
{ xle29:?l
String header=con.getHeaderFieldKey(i); {HU48v"W
if(header!=null) 9e5UTJ
//responseHeaders.put(header,httpConnection.getHeaderField(header)); b2Hpuej
Utility.log(header+" : "+con.getHeaderField(header)); 5 9vGLN!L
else pi{ahuI#_o
break; o(zg_!P
} 8HOmWQS
} ]5\vYk
Pla EI p
pDLo`F}A
public void splitterStop() t]ZSo-
{ 7ou^wt+%
bStop = true; $3ILVT
} `jHGNi
3C2>
qrkT7f
} 8\9EDgT
;GAYcVB
K0\WN"ua;
/* rBf?kDt6l
**FileAccess.java )3AT=b
*//文件访问(定位，写) hA8 zXk/'8
package NetFox; !iw 'tHhR
import java.io.*; Q [{vU
7E95"B&w
bv/b<N@4?$
public class FileAccessI implements Serializable{ 1GdD
W<Lrfo&=Y]
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 '}u31V"SS
RandomAccessFile oSavedFile; g&>Hy!v,
long nPos; (=j!P*
!UTJ) &
l5FQ!>IM
public FileAccessI() throws IOException 6{'6_4;Fv(
{ tOw 0(-:iq
this("",0); MlFvDy
} D;]%
`?x$J 6p
)^TQedF
public FileAccessI(String sName,long nPos) throws IOException 9f\8oJQ
{ kP$gl|
oSavedFile = new RandomAccessFile(sName,"rw"); YkX=n{^
this.nPos = nPos; d]EvC>
oSavedFile.seek(nPos); w>uZ$/
} b U NYTF{
DOeKW
fXe-U='
public synchronized int write(byte[] b,int nStart,int nLen) ^A`(
{ {M/c!
int n = -1; k5D'RD
try{ 9#ft;c
oSavedFile.write(b,nStart,nLen); pm\X*t}L
n = nLen; {R;M`EU>
} s.'\&B[
catch(IOException e) x[UO1% _o-
{ I})t
e.printStackTrace (); K/`RZ!
} GDp p`'\
YS~t d+*
Aw;vg/#~md
return n; ?bAFYF0!I
} :-La $I>
&pjV4m|j<
Z4ioXl
} mndl~/
@BUqQ9q:
*`Xx_
/* vN:[
**SiteInfoBean.java +wozjjc
*/ ?i2Wst
package NetFox; 4UjE*Aq
3]n@c?lw
n~u3
public class SiteInfoBean { m\M+pjz
Uy5!H1u
+\GZ(!~
private String sSiteURL; //Site's URL ,,%:vK+V
private String sFilePath; //Saved File's Path 2BX GVo
private String sFileName; //Saved File's Name c[_^bs>k
private int nSplitter; //Count of Splited Downloading File `(/saq*
8sIA;r%S
<3=qLm
public SiteInfoBean() kN|5 J
{//nSplitter的缺省值为5 5}bZs` C
//default value of nSplitter is 5 nVn|$ "r
this("","","",5); =yX&p:-&
} V!77YFen %
F4E3c4 81
yISQYvSN
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) |W*@}D
{ L3GC[$S
sSiteURL= sURL; hr4ye`c j
sFilePath = sPath; b>=Wq
sFileName = sName; {XD/8m(hN|
this.nSplitter = nSpiltter; ct}%Mdg
KU|BT.o8
dG-or
} yvd `nV
!3I(4?G,
/8>0;bX+
public String getSSiteURL() poQdI?ed,
{ YYE8/\+B.
return sSiteURL; Cb{A:\>Q{
} +an^e'
]oeuIRyQ
u-QO>3oY6
public void setSSiteURL(String value) )?B~64N,+
{ b-BM"~N'
sSiteURL = value; _+\:OB[Y
} f(6UL31
Xqg.kX
:'y{dbKp"
public String getSFilePath() vS$oT]-hKE
{ 97Zk P=Cq
return sFilePath; 3WCqKXJ7
} m0|Ae@g~3
g=xv+e
,2,SG/BB
public void setSFilePath(String value) qE0FgqRB
{ #dZ/UM(u
sFilePath = value; \5Vp6^
} T9z4W]T
my ;
_{e&@d
public String getSFileName() =a)iVXSB]
{ crd|2bjp+
return sFileName; w%3Fg~Up
} ~V2ajM1Z&O
/M^V2=
L\b]k,Ksf
public void setSFileName(String value) -BA"3 S
{ 731h ~x!u
sFileName = value; b/sOfQ
} XogvtK*
"xvtqi,R
x.b; +p}=
public int getNSplitter() H>?:U]
{ Opv1B2
return nSplitter; \6 \hnP
} ;Z ]<S_#-
e0f":Vct
rH9uGm-*
public void setNSplitter(int nCount) w]};0v&\~s
{ #)GW}U]X
nSplitter = nCount; ^^G-kg
} })@tA<+
} 2)wAFO6u
&/s~? Iq
aS,a_b]
/* i?F[||O"$
**Utility.java u4:\UC'
*/ br0u@G
package NetFox; /61by$E
~|&="K4,:
f hQy36i@
public class Utility { FZiZg;
* [tc
(cvh3',
public Utility() pd d|n2q
{ %=V"CJ$|
[UMLx
On=u#DxQ
} -b cG[W3
<eY%sFq,
//线程睡眠 <B!'3C(P
public static void sleep(int nSecond) Z<;U:aH?}
{ `dDa}b
try{ )s7bJjT0=X
Thread.sleep(nSecond); *zq.C
} qxfLfgu^
catch(Exception e) & g:%*>7P
{ ]}kI)34/
e.printStackTrace (); X~lZOVmS
} czI{qi5N
} S?L#N
+0J@y1
//日志 6mCq/$
public static void log(String sMsg) X8Xn\E
{ MM#i t=u
System.err.println(sMsg); ,9mgYp2
} Sk\n;mL:
p%F8'2)}
#$FrFU;ZR
public static void log(int sMsg) Pp+~Cir
{ FEF"\O|Q
System.err.println(sMsg); 9JPEj-3`g
} gE\b982
} zsDocR
(YwalfG {C
oV9z(!X/
/* w$j{Hp6m
**TestMethod.java D+sQPymI
*/ l&L,7BX
package NetFox; o'Wz*oY))\
yHNuU)Ft
8Atq,GcG
public class TestMethod { :=<0=JE#
jY/ARBC}H
^gOww6$<
public TestMethod() ,[isib3
{ ///xx/weblogic60b2_win.exe YLOwQj'
try{ s\gp5MT
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); S/4r\6
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); uvnI>gv
SiteFileFetch fileFetch = new SiteFileFetch(bean); cJDd0(tD!
fileFetch.start(); ~~nqU pK?v
} NvJV</l6A
catch(Exception e){e.printStackTrace ();} I{ ryD -!
1u~ MXGF
f+x;:
} ~$<UE}qp
yK1ie
>2b`\Q*<
public static void main(String[] args) PD6_)PXn
{ j*400
new TestMethod(); M;jcUX_{
} gEwd &J
} sw;|'N$:<
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