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)); &A"e,h(^
} tE:X,Lt[
for(int i=0;i<nEndPos.length-1;i++) H56 ^n<tg
{ -,/3"}<^78
nEndPos = nStartPos[i+1]; !2tw,QM
} =43d%N
nEndPos[nEndPos.length-1] = nFileLength; Tc,$TCF
} o4'Wr
} Oc^m_U8>^
&GU@8
bx7\QU+
//启动子线程 hpjUkGm5
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; `x4E;Wjv
for(int i=0;i<nStartPos.length;i++) hA5,w_G/
{ Q,n4i@E
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), Q!x`M4
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), IwM8#6;S~
nStartPos,nEndPos,i); CfY7<o1>
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); hU)'OKe
fileSplitterFetch.start(); bHJoEYY^
} Y.9~Bo<<r
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), \KNdZC?V2
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); 4$F:NW,v:)
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", W'V@
nEndPos = " + nFileLength); pEkOSG
// fileSplitterFetch[nPos.length-1].start(); `1$y(w]
iz$FcA]
0&Qsk!-B
//等待子线程结束 `>\4"`I
//int count = 0; +/w(K,
//是否结束while循环 ^ePsIl1E
boolean breakWhile = false; 33,;iE
QS5H>5M)
;n` $+g:>
while(!bStop) ;*.(.
{ cP,;Qbe
write_nPos(); |&Au63
Utility.sleep(500); &q"'_4
breakWhile = true; |@+8]dy:l
C#ZhsWS!b
;C+cE#
for(int i=0;i<nStartPos.length;i++) X:R%1+&*
{ 'HJ/2-=
if(!fileSplitterFetch.bDownOver) z^gi[ mi
{ fWd~-U0M^
breakWhile = false; ,zG<7~m
break; b#Jo Xa9
} g%X&f_@
} 9e-*JYF]C
if(breakWhile) R04.K!
break; xcw%RUC-
<sO?ev[
Gee~>:_Q{J
//count++; ?_8%h`z
//if(count>4) ]c5DOv&
// siteStop(); &K+
} dFx2>6AZt
i^/ eN
1!X1wCT
System.err.println("文件下载结束！"); %A8Pkr<&E
} E!dz/.
catch(Exception e){e.printStackTrace ();} :jBZK=3F>
} +:fqL
C:rRK*
k& WS$R?u
//获得文件长度 $Z,i|K;
public long getFileSize() A*rZQh b[
{ -l\~p4U
int nFileLength = -1; Hde]DK,d
try{ $*YC7f
URL url = new URL(siteInfoBean.getSSiteURL()); N 9c8c
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); j?Cr31
httpConnection.setRequestProperty("User-Agent","NetFox"); C usVW
di"C]" ;
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int responseCode=httpConnection.getResponseCode(); DLNa6
if(responseCode>=400) i:V0fBR[>
{ c9\B[@-q
processErrorCode(responseCode); 6e-#XCR{
return -2; //-2 represent access is error wCV>F-
} l.XknF
<Gn8B^~$
M4zX*&w.T
String sHeader; F9Ifw><XM
xN e_qO
=''mpIg(
for(int i=1;;i++) ~!8%_J_
{ hZp=BM"bJ
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); *eHA: A_I
//Utility.log(in.readLine()); 8FxcI!A@
sHeader=httpConnection.getHeaderFieldKey(i); ,:v.L}+Z
if(sHeader!=null) .tZjdNE(h
{ fKPiRlLS
if(sHeader.equals("Content-Length")) ^zvA?'s
{ jz|Wj
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); AeNyZ[40T
break; C>.]Bvg
} 1;cv-W
} >v^2^$^u
else ML=hKwCA
break; 1bV2
} cxtLy&C
} BengRG[
catch(IOException e){e.printStackTrace ();} ?R|fS*e2EB
catch(Exception e){e.printStackTrace ();} @?<N +qdH>
/Oq1q._9F
S% JNxT7'
Utility.log(nFileLength); 2uvQf&,
^m6k@VM
ddUjs8VvJ
return nFileLength; LVPt*S=/
} NWo7wVwc/c
L LYHr
i1b4 J
//保存下载信息（文件指针位置） L eG7x7n
private void write_nPos() '#cT4_D^lI
{ |y{;|K
try{ tx:rj6-z
output = new DataOutputStream(new FileOutputStream(tmpFile)); F|]o9&/<]
output.writeInt(nStartPos.length); l%sp[uqcg
for(int i=0;i<nStartPos.length;i++) j33P~H~
{ 6MLN>)t
// output.writeLong(nPos); w5dIk]T
output.writeLong(fileSplitterFetch.nStartPos); 1R5\GKF6o
output.writeLong(fileSplitterFetch.nEndPos); -4*'WzWr
} "TBQNWZ
output.close(); /RA1d<~$q
} Vu|Br
catch(IOException e){e.printStackTrace ();} veYsctK~
catch(Exception e){e.printStackTrace ();} ^DW#
} !wLH&X$XT
eZN3H"H
*j_fG$10g
//读取保存的下载信息（文件指针位置） IyG= 7
private void read_nPos() |xsV(jK8
{ $nGbT4sc
try{ j=xtnIq
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); v@$evmA
int nCount = input.readInt(); wzHjEW
nStartPos = new long[nCount]; zCBtD_@
nEndPos = new long[nCount]; 5`{|[J_[
for(int i=0;i<nStartPos.length;i++) W%cj39$
{ +!L_E6pyXE
nStartPos = input.readLong(); ?RRSrr1
nEndPos = input.readLong(); 66^1&D"
} h30QCk
input.close(); |l6<GWG+
} m'Ekp
catch(IOException e){e.printStackTrace ();} BDRYip[Sa
catch(Exception e){e.printStackTrace ();} (l3UNP
} dVsAX(
K\^&_#MG
6yu*a_
private void processErrorCode(int nErrorCode) b2}QoJ@`
{ yv!''F:9F
System.err.println("Error Code : " + nErrorCode); A/$KA'jX
} gq/ePSa
CD8JYiJ
7'{Yz
//停止文件下载 Ew?/@KAV\
public void siteStop() c5=v`hv
{ h87L8qh9
bStop = true; 48~m=mI
for(int i=0;i<nStartPos.length;i++) 2#n$x*CY
fileSplitterFetch.splitterStop(); :bM$;
+QXYU8bYZ
ArmL,
} o%4&1^ Vg
} _} X`t8Lh
//负责部分文件的抓取 TN |{P
**FileSplitterFetch.java ?(,5eg
*/ 1VjeP *
package NetFox; zNsL^;uT
3'sWlhf;
uZ0 $s$
import java.io.*; D25gg
import java.net.*; 3f:1D=f
];b!*Z
Zm; +Ku>
public class FileSplitterFetch extends Thread { ZB^4(F')H
2,XqslB)
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String sURL; //File URL W &0@&U
long nStartPos; //File Snippet Start Position #H|j-RM2
long nEndPos; //File Snippet End Position qh(-shZ4Du
int nThreadID; //Thread's ID [BZ(p
boolean bDownOver = false; //Downing is over rt@-Pw!B
boolean bStop = false; //Stop identical SbPjU50
FileAccessI fileAccessI = null; //File Access interface vU$O{|J
hml\^I8Q>F
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public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException Y3MR:{}
{ ,5<`+w#a
this.sURL = sURL; !iitx U
this.nStartPos = nStart; li_pM!dWU_
this.nEndPos = nEnd; 2$i 0yPv
nThreadID = id; AXU!-er$
fileAccessI = new FileAccessI(sName,nStartPos);//定位 WlQ&Yau
} xwH|ryfs,Z
<1g1hqK3
b1,T!xL
public void run() Lx:9@3'7'
{ v/TlXxfil
while(nStartPos < nEndPos && !bStop) ETWmeMN
{ ,?~UpsUx
}b]y 0"
sO4}kxZ
try{ ^SSOh#
URL url = new URL(sURL); _F|_C5A
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); w6In{uO-Z
httpConnection.setRequestProperty("User-Agent","NetFox"); mKFHT
String sProperty = "bytes="+nStartPos+"-"; ]BQWA
httpConnection.setRequestProperty("RANGE",sProperty); >/HU'
Utility.log(sProperty); 'ZZWH
:qSi>KCGh
v"('_!
InputStream input = httpConnection.getInputStream(); io?{ew
//logResponseHead(httpConnection); f_P+qm
-IsdU7}
9@z|2z2\G
byte[] b = new byte[1024]; I'%H:53^0
int nRead; }Ka.bZS
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) ZRq}g:
{ bZ22O"F
nStartPos += fileAccessI.write(b,0,nRead); /'=^^%&:B
//if(nThreadID == 1) & Dl'*|
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 19-yM`O
} h`;F<PFW
9oxf)pjw
KsU&<eQ
Utility.log("Thread " + nThreadID + " is over!"); iN/!k.ybW}
bDownOver = true; dpn&)?f
//nPos = fileAccessI.write (b,0,nRead); K84cE
} rKs WS~U
catch(Exception e){e.printStackTrace ();} *0@; kD=
} b%jG?HSu
} mF:s-+
`::'UfHc
V #\ZS{'J
//打印回应的头信息 ?gMrcc/{
public void logResponseHead(HttpURLConnection con) 2gR_1*|
{ oS|~\,p"
for(int i=1;;i++) . .je<
{ ,~?A. 5
String header=con.getHeaderFieldKey(i); c^)E:J/
if(header!=null) yr 9)ga%
//responseHeaders.put(header,httpConnection.getHeaderField(header)); !#gE'(J;c
Utility.log(header+" : "+con.getHeaderField(header)); `iayh
else +X(^Q@
break; QOy&!6
} 'CAukk|
} 4e\`zy
s=Q*|
yy.:0:ema
public void splitterStop() `ur9KP4Dq
{ [qMO7enu#
bStop = true; /F}\V ^
} N\e@$1
k^\&.63(
9Kx:^~}20o
} gN'i+mQcu
.%b_3s".
Qr-J-2s?B
/* *vE C,)
**FileAccess.java K2K6
*//文件访问(定位，写) EAE\Xv
package NetFox; (E(:F[.S
import java.io.*; g E+OQWu
i/Lq2n3 )
EI+/%.,
public class FileAccessI implements Serializable{ dq/?&X
]3u'Qv}o
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 gOmyFHv.
RandomAccessFile oSavedFile; 9<c4y4#y
long nPos; ;C3?Ic
FS+^r\)
< LAD
public FileAccessI() throws IOException nGgc~E$j
{ Kf^F#dA
this("",0); '#::ba[9w
} 24/~gft
koY8=lh/
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public FileAccessI(String sName,long nPos) throws IOException )stWr r&
{ oxXW`C<
oSavedFile = new RandomAccessFile(sName,"rw"); B{(l5B6
this.nPos = nPos; )nxIxr0d-
oSavedFile.seek(nPos); )K3 vzX
} TN aff
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Cfb-:e$0
public synchronized int write(byte[] b,int nStart,int nLen) b/Q"j3
{ V46[whL%r
int n = -1; lS-i9U/,>
try{ |o) _=Fx
oSavedFile.write(b,nStart,nLen); n(S-F g
n = nLen; me^Gk/`Em
} _cN)q
catch(IOException e) `~TGVa`D
{ *sVxjZvV
e.printStackTrace (); q#-H+7 5
} "0)G|pZI
1A.\Ao
.cog9H'
return n; o}Np}PE6
} 1*b%C"C
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bA,D]
} ofCP>Z-
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/2cOZ1G;
/* f L?~1i =
**SiteInfoBean.java dsuW4^l
*/ h1)\.F4G
package NetFox; `2
+t{FF!mL
imQNfNm
public class SiteInfoBean { uB5o Ghu-
_lqAxWH
LnX^*;P5t
private String sSiteURL; //Site's URL *E_= 8OV
private String sFilePath; //Saved File's Path %*=FLtBjo
private String sFileName; //Saved File's Name kICYPy
private int nSplitter; //Count of Splited Downloading File ^KR(p!%
pl&GFf o
(6'Hzl^Kp
public SiteInfoBean() ,Z"sh*
{//nSplitter的缺省值为5 R!CUR~F
//default value of nSplitter is 5 2eYkWHi
this("","","",5); 6fyW6xv[,
} | 'G$}]H
5w3'yA<vE
t[~i})yS
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) \v Go5`
{ 4R6 .GO
sSiteURL= sURL; rD?o97
sFilePath = sPath; JJXf%o0yq
sFileName = sName; "p\KePc;@
this.nSplitter = nSpiltter; (fS4qz:&l
S)?B I
T^t`Hp
} Ycm1 _z
&(0);I@fc
qm@hD>W+
public String getSSiteURL() mi?Fy0\
{ 4 @h6|=
return sSiteURL; WxdYvmp6z[
} V qf}(3K0
[gDvAtTZ5
EBm\rM8
public void setSSiteURL(String value) zi'?FM[f)
{ ;F5%X\t-
sSiteURL = value; l8Ox]%F
} @EvnV.
<?eZ9eB
[z?XVl<
public String getSFilePath() <e"2<qVi
{ 4Y'qoM;
return sFilePath; {^v50d
} 6K&V}
f;*\y!|lg~
wTLHg2'y^
public void setSFilePath(String value) N4r`czoj
{ F!U+IztZ
sFilePath = value; sfH|sp
} 6sntwT"?
WZZD
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public String getSFileName() tcs Z!#
{ q\ ?6-?Mr
return sFileName; 15870xS
} aJ2-BRn
tTY(I1
^0VI J)y
public void setSFileName(String value) O32:j
{ ";Lpf]<
sFileName = value; +* &!u=%G
} 1w35H9\g
Y40{v(Pi
M6?*\9E
public int getNSplitter() :.@gd7T
{ {BgGG@e
return nSplitter; #[2]B8NZ
} Z$T1nm%lo:
8K{ TRPy
NoV2<m$
public void setNSplitter(int nCount) WPLAh_fe
{ m39 `f,M
nSplitter = nCount; z!eY=G'
} 7` &K=( .
} &c0U\G|j
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:FB#,AOa_
/* wS#.Wzp.w
**Utility.java dtr8u
*/ RD<l<+C^~
package NetFox; //Ck1cI#h
a6fMx~
$Ic: c
public class Utility { \-gZ_>)
noV]+1#"V
I HgYgn
public Utility() H0_hQ:K
{ W/OZ}ky}^
t?iCq1
aPWlV= oG
} L]I)E`s
q;1]M[&
//线程睡眠 ayTEQS
public static void sleep(int nSecond) i!@L`h!rw
{ =Wn11JGh
try{ >r6`bh [4
Thread.sleep(nSecond); CXwDG_e
} 9 N[k ?kUZ
catch(Exception e) +}@1X&v:
{ 5B)Z@-x2
e.printStackTrace (); ^NKB
} t>:2F,0K9
} ~_OtbNj#
OsAH!e
//日志 A8Tq2]"* S
public static void log(String sMsg) SO^:6GuJ
{ o[pv.:w
System.err.println(sMsg); Au(zvgP
} r*'a-2Au
_7Z|=)
pVbgjJI
public static void log(int sMsg) _PUgK\
{ N'[bA
System.err.println(sMsg); AvnK?*5!@
} R%B"Gtl)
} QwPLy O
$J}d6%
=g|e-XC
/* ~H"Q5Hr
**TestMethod.java r:Uqtqxh
*/ } m5AO4:
package NetFox; ,Yx"3i,
el GP2x#:
AfAg#75q
public class TestMethod { &-^|n*=g6
4JF)w;X}
W+N9~.q\^
public TestMethod() m]LR4V6k|
{ ///xx/weblogic60b2_win.exe IO/%X;Y_
try{ 022nn-~
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); Bc1[^{`bq^
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); P=v 0|Y*q|
SiteFileFetch fileFetch = new SiteFileFetch(bean); (Ic{C5'
fileFetch.start(); $@]tTz;b
} 'nH/Z 84
catch(Exception e){e.printStackTrace ();} xRum q
qm30,$\c`~
^@W98_bd;
} F!v`._]
/58]{MfrJ
^(,qkq'u D
public static void main(String[] args) s"1:#.u
{ w.s-T.5.j
new TestMethod(); 77y_?di^I
} -mD<8v[F
} Yt^<^l77D
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