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)); So:X!ljN(e
} >}5?`.K~Q*
for(int i=0;i<nEndPos.length-1;i++) X/!_>@`7?
{ xad`-vw
nEndPos = nStartPos[i+1]; Jh[0xb
} Onmmcem
nEndPos[nEndPos.length-1] = nFileLength; Bd>~F7VWs
} @Mk`Tl
} [oWkd_dK
Bqx5N"
%!|w(Povq
//启动子线程 }d$-:l,w
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; EM,C
for(int i=0;i<nStartPos.length;i++) Tc2.ciU
{ 7#8Gn=g
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), f60w%
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), b@:OlZ~%
nStartPos,nEndPos,i); c]=2>ov)hR
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); ">A<%5F2
fileSplitterFetch.start(); 5&Oc`5QD
} 4aayMS!#
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), rk=D5E7
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); ^xo<$zn
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", .nV2n@SR
nEndPos = " + nFileLength); Ebg8qDE
// fileSplitterFetch[nPos.length-1].start(); 5/H,UL
,'#TdLe
|dRVSVN
//等待子线程结束 3"fDFR
//int count = 0; Et>#&Nw8
//是否结束while循环 qTO6I5u
boolean breakWhile = false; OLw]BJXYaE
xm'9n?
@sXFu[!U
while(!bStop) _vQ52H,
{ D0. )%
write_nPos(); %E?Srs}j
Utility.sleep(500); Vns3859$8
breakWhile = true; vSzpx
t0)1;aBZ
VK}4<u
for(int i=0;i<nStartPos.length;i++) 8&<:(mAP
{ rTD+7 )E
if(!fileSplitterFetch.bDownOver) O"m7r ds
{ wjarQog5Y
breakWhile = false; =u~nLL
break; Lx"GBEkt7
} q*!R4yE;C
} )m%uSSx#
if(breakWhile) %1z;l.c
break; MqmQ52HR
Z:4/lx7Bq
,GbmL8P7Y
//count++; 56.!L
//if(count>4) 0RR|!zEu
// siteStop(); m_NX[>&Y3
} `FHudSK
.?>Cav9:
ldv@C6+J
System.err.println("文件下载结束！"); <O#&D|EMd|
} ^BsT>VSH6
catch(Exception e){e.printStackTrace ();} *dBy<dIy
} 3bEcKA_z(
d\z6Ob"t
=j7Du[?Vu
//获得文件长度 (f/(q-7VWt
public long getFileSize() -YoL.`s1
{ w,{h9f
int nFileLength = -1; XcR=4q|7
try{ ^'UM@dd?!
URL url = new URL(siteInfoBean.getSSiteURL()); N['DqS =
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 1v@#b@NXM7
httpConnection.setRequestProperty("User-Agent","NetFox"); W/'1ftn?D
Mw[3711v
j,n:%5P\v
int responseCode=httpConnection.getResponseCode(); Xfiwblg
if(responseCode>=400) *yq65yZi5
{ {q>%Sr]9
processErrorCode(responseCode); 1\hLwG6Jj
return -2; //-2 represent access is error 0Tj,TF
} CTMC78=9}
Nc[@QC{
LF|0lAr
String sHeader; ^:9a1{L[
r"H::A
1;B~n5C.
for(int i=1;;i++) \aSP7DzqQ
{ m^X51,+<
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); )g5?5f;
//Utility.log(in.readLine()); ;0DoZ
sHeader=httpConnection.getHeaderFieldKey(i); 9>RkFV
if(sHeader!=null) tBo\R?YRs
{ An2>]\L
if(sHeader.equals("Content-Length")) -cqE^qAdX
{ z?/_b
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); a~}q]o?j
break; $4bc!
} 7FX4|]
} Pz)lq2Zm9
else h nydH-;cz
break; @]uqC~a^
} g*k)ws
} AXyXK??
catch(IOException e){e.printStackTrace ();} B,b8\\^k|
catch(Exception e){e.printStackTrace ();} "Eh=@?]S_
J)nK9
mhbczVw
Utility.log(nFileLength); Bdo{zv&A
y r (g/0
5F kdGF
return nFileLength; F5)`FM^R
} x&B&lFmo8
!do`OEQKR
KEAXDF&#
//保存下载信息（文件指针位置） vCa8`m
private void write_nPos() 3%v)!dTa<^
{ ==Gc%
try{ 4uF.kz-cg
output = new DataOutputStream(new FileOutputStream(tmpFile)); 8Vu@awz{L
output.writeInt(nStartPos.length); ^ h=QpH
for(int i=0;i<nStartPos.length;i++) 2D 4,#X
{ LV}R 9f
// output.writeLong(nPos); SYJO3cY
output.writeLong(fileSplitterFetch.nStartPos); -()WTdIy
output.writeLong(fileSplitterFetch.nEndPos); Xv1vq -cM
} m*^)#
output.close(); 7_~ A*LM
} _i_='dsyW/
catch(IOException e){e.printStackTrace ();} Cqd\n#d/~
catch(Exception e){e.printStackTrace ();} d/_D|ivZ=
} ki1(b]rf
x0j5D
P&`%VW3E
//读取保存的下载信息（文件指针位置） v9(5HY
private void read_nPos() RZ6y5
{ rr#nBhh8
try{ 9r%fBiSk
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); t]K20(FSN
int nCount = input.readInt(); B{Q}^Mcxy
nStartPos = new long[nCount]; <rC%$tr
nEndPos = new long[nCount]; o.KnDY
for(int i=0;i<nStartPos.length;i++) U[C>Aoze
{ 5|*{~O|
nStartPos = input.readLong(); d4o ^+\
nEndPos = input.readLong(); 2A_1E\
} MQ,K%_m8
input.close(); IQ&PPC
} eV7;#w<]
catch(IOException e){e.printStackTrace ();} Vr2A7kq
catch(Exception e){e.printStackTrace ();} a4:GGzt
} 0ix(1`Z
>u=
tN#C.M7.'7
private void processErrorCode(int nErrorCode) C?qRZB+W#
{ 1UP {j`-K|
System.err.println("Error Code : " + nErrorCode); 6_mi9_w
} h<9vm[.
w/@ZPBRo]
n#!c!EfG
//停止文件下载 }s,NM%oI
public void siteStop() F ~A$7
{ f' A$':Y
bStop = true; !MoAga_ j
for(int i=0;i<nStartPos.length;i++) ^4=#,K
fileSplitterFetch.splitterStop(); \,S|>CPQ
9'MGv*Ho
ni;)6,i
} z;JV3)E
} @]qP:h.
//负责部分文件的抓取 =l(euBb
**FileSplitterFetch.java 1PY]Q{r
*/ zPnb_[YF
package NetFox; ^ZMbJe%L
rrL.Y&DTK
[,Ehu<mEK
import java.io.*; LR=Ji7
import java.net.*; $RDlM
IuY9Q8
etX@z'H
public class FileSplitterFetch extends Thread { /8;m.J>bf
/&Q{B f
TcZ.5Oe6h#
String sURL; //File URL >pu4G+M
long nStartPos; //File Snippet Start Position /3s&??{tv
long nEndPos; //File Snippet End Position HV%/baX]
int nThreadID; //Thread's ID xPZ>vCg
boolean bDownOver = false; //Downing is over 1Uup.(
boolean bStop = false; //Stop identical *}2L4]
FileAccessI fileAccessI = null; //File Access interface ]i {yJ)i
vW?\bH7}I
kZe<<iv
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException <7P[)X_
{ q>_<\|?%x
this.sURL = sURL; mZ71_4X#
this.nStartPos = nStart; *RkUF!)(
this.nEndPos = nEnd; }MaY:PMA
nThreadID = id; WW:G( \`
fileAccessI = new FileAccessI(sName,nStartPos);//定位 ^ ]9K>}
} Snk+ZQ-
bK:U:vpYm
,rMDGZm?
public void run() 6Vnq|;W3Zv
{ $udhTI#,
while(nStartPos < nEndPos && !bStop) 44KoOY_
{ N3"JouP
<0d2{RQ;
40?RiwwD
try{ qyM/p.mP
URL url = new URL(sURL); J>(X0@eWz
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); TuQGF$n@
httpConnection.setRequestProperty("User-Agent","NetFox"); QIiy\E%
String sProperty = "bytes="+nStartPos+"-"; h0<PQZJ
httpConnection.setRequestProperty("RANGE",sProperty); ROFZ*@CH<
Utility.log(sProperty); q-!H7o
F85_Lz4
'=0}2sF>
InputStream input = httpConnection.getInputStream(); OZ\6qMH3e
//logResponseHead(httpConnection); `,]Bs*~
H,}&=SCk
jn^X{R\
byte[] b = new byte[1024]; %,bD| NKp
int nRead; -rO34l
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) Db"mq'vT
{ UDEGQ^)Xz|
nStartPos += fileAccessI.write(b,0,nRead); t@!n?j I
//if(nThreadID == 1) ?%5VaxWJ
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); OcL7] b0
} e|Ri
;M?)-dpZ
<>6j>w_|
Utility.log("Thread " + nThreadID + " is over!"); rpKZ>S|7+)
bDownOver = true; nJe}U#
//nPos = fileAccessI.write (b,0,nRead); =zFROB\
} AJ7w_'u=@
catch(Exception e){e.printStackTrace ();} %)j&/QdzF&
} v@$N,g
} 9JFN8Gf*)
m?kiGC&m
!AwMD
//打印回应的头信息 uG\~Hxqw7O
public void logResponseHead(HttpURLConnection con) *I 1H
{ X%b1KG|#(
for(int i=1;;i++) %mC@}
{ ny{C,1QG
String header=con.getHeaderFieldKey(i); L('1NN2
if(header!=null) (fpz",[
//responseHeaders.put(header,httpConnection.getHeaderField(header)); )'kpO>_G
Utility.log(header+" : "+con.getHeaderField(header)); _V$'nz#>e
else 4<Vi`X7[F
break; M FIb-*wT
} V}V->j*
} !Ubm 586!
necY/&Ld-
2iNLm6"
public void splitterStop() W{;Qi&^ca
{ (p2`ofj
bStop = true; :u4|6?
} AA5G`LiT
a/ Ac^!(
ko@ej^
} L"ho|v9:
`N\ ^JAGW
:9QU\{2
/* g`pq*D
**FileAccess.java mn@1&#c4y
*//文件访问(定位，写) ZeV@ X
package NetFox; S"!6]!~^
import java.io.*; ZN8j})lE
YNBM\Q
r~,y3L6ic
public class FileAccessI implements Serializable{ X9| Z?jJ
R&cTMd
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 vgeqH[:
RandomAccessFile oSavedFile; *aCL/:
long nPos; =d8Rij-
+0Q
:^y!z1\2(7
public FileAccessI() throws IOException lgews"
{ WX4sTxJK
this("",0); TOHz3=
} >SXSrXyYX
k>ErDv8
b/_Zw^DPC
public FileAccessI(String sName,long nPos) throws IOException `Moo WG
{ \9[vi +T
oSavedFile = new RandomAccessFile(sName,"rw"); RQE]=N
this.nPos = nPos; cb_C2+%8NA
oSavedFile.seek(nPos); CtY-Gs
} kQ>2W5o-d-
|5vcT,A
{($bzT7c
public synchronized int write(byte[] b,int nStart,int nLen) Mqr]e#"o
{ F?6kkLS/
int n = -1; EA~xxKq
try{ d[t0K]
oSavedFile.write(b,nStart,nLen); _s;y0$O
n = nLen; Q# hRnM
} 6Rfv3
catch(IOException e) !` 1h *}
{ oEX,\@+u
e.printStackTrace (); \kQ)fk]^
} ]~;*9`:
"-f]d~P>
k^}[+IFJ
return n; -f|/#1
} SNqSp.>-U"
1NP
~DD _n
} "]"0d[d
kZF]BPh.
\oPe"k=
/* _4>DuklH,
**SiteInfoBean.java ;"&?Okz
*/ p&Qb&nWk<
package NetFox; .OJGo<#$f
0se%|Z|8
F/2cQ.u2
public class SiteInfoBean { tz]0F5
o'lG9ePM|
`p\%ha!,w
private String sSiteURL; //Site's URL /D"T\KNWr
private String sFilePath; //Saved File's Path im*sSz 0 (
private String sFileName; //Saved File's Name 7=fM}sk
private int nSplitter; //Count of Splited Downloading File "\*)KH`C
a>GA=r
^x&x|ckR!
public SiteInfoBean() DG;u_6;JR
{//nSplitter的缺省值为5 =\]gL%N-|
//default value of nSplitter is 5 Gxd/t#;
this("","","",5); 4&NB xe
} "5eD >!
_ %mm
W_XFTqp^
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) 2M+RA}dX
{ @ fMlbJq
sSiteURL= sURL; G5qsnTxUJ
sFilePath = sPath; ^U~Er'mT
sFileName = sName; Wqv7
this.nSplitter = nSpiltter; ~"S5KroN
m LajiZ Bf
o2(w
} AkW,Fp1e
-v9(43
cPIyD?c
public String getSSiteURL() L^e*_q2d:>
{ 2>"{El|PbN
return sSiteURL; HV!P]82Pa
} Jha*BaD~N
U+VJiz<!
<@`K^g;W
public void setSSiteURL(String value) ]}SV%*{%
{ R{}_Qb
sSiteURL = value; !& c%!*
} > X AB#
(NUXK
f]1 $`
public String getSFilePath() o,k#ft<
{ +PYR
return sFilePath; p3fVw]N
} >]}VD "\
RCqL~7C+ k
3Dc^lfn
public void setSFilePath(String value) ~@@t-QY
{ vasw@Uto)
sFilePath = value; toF6 Z
} 'NWvQR<X
BfCib]V9C
=SJ[)|
public String getSFileName() |QzJHP @
{ ' Sd&I:?
return sFileName; h%:wIkZ/
} a:|]F|
b c .Vy
CWs;1`aP
public void setSFileName(String value) *RkvM?o@jC
{ ~=wBF
sFileName = value; ,hK =x
} mp3Dc
7TAoWD3
a w~a/T:
public int getNSplitter() JF&$'
{ k'$7RjCu
return nSplitter; lItr*,A]
} =uwG.,lC
BvlY\^
6:r1^q6A9L
public void setNSplitter(int nCount) /x-tl)(s=
{ ICoZ<;p
nSplitter = nCount; FlS)m`
} ?Wt_Obl
} Rpcnpo
2b {Y1*
EI9Yv>7d{
/* yyR@kOGga
**Utility.java Zfu" 8fX
*/ W6B o\UK
package NetFox; !/&~Feb
tORDtMM9+
GmGq69]J*
public class Utility { n;b9f|&z
fZd~},X
:+DAzjwO<
public Utility() :?%_JM5U
{ >fR#U"KPAB
b=Sl`&A
mR{%f?B
} y(#F&^|
hYCyc-W
//线程睡眠 GLl@ 6S>v
public static void sleep(int nSecond) ZG)C#I1;O
{ Jf2:[Mq
try{ N_!Zn"J
Thread.sleep(nSecond); of<>M4/g4y
} Iq": U
catch(Exception e) 9aqFdlbY
{ ~?A,GalS
e.printStackTrace (); cmh/a~vYaY
} I|[aa$G
} ?yz}
NOmSLIgt7
//日志 j1toV$)P
public static void log(String sMsg) 28+Sz>SP
{ y+iuA@WCv
System.err.println(sMsg); 0H.B>:pv
} fs]Zw mA^
&sA6o"h~
~pSD|WX
public static void log(int sMsg) &9] [~$
{ .J\U|r
System.err.println(sMsg); >-y&k^a=
} <Q-ufF85)
} Mz{ Rh+gS
:S7yM8b`
skP_us~
/* /C8(cVNZ
**TestMethod.java W%Zyt:H`
*/ Zk;;~ESOU
package NetFox; kk5i{.?[
1}q[8q
vrW9<{
public class TestMethod { k0D&F;a%
!xqG-rd '
kAk,:a;P
public TestMethod() R QO{fC
{ ///xx/weblogic60b2_win.exe NtOR/*
try{ VZlvmN
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); E[Io8|QA
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); %J%gXk}]
SiteFileFetch fileFetch = new SiteFileFetch(bean); :~)Q]G1Nj
fileFetch.start(); $v oyXi`*
} +#H8d1^5
catch(Exception e){e.printStackTrace ();} izWl5}+'B
3S2'JOTY
~ pdf'
} \M532_w
6k3l/~R
fAUsJ[
public static void main(String[] args) s*YFN#Wuc
{ ujWHO$uz!
new TestMethod(); S@"=,Xj M
} K;xW/7?
} ta6WZu
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