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)); Z&of-[)
} &B\ sG=
for(int i=0;i<nEndPos.length-1;i++) 0X:$ASocU
{ Y@Ur}
nEndPos = nStartPos[i+1]; e}+Zj'5
} _FxeZ4\
nEndPos[nEndPos.length-1] = nFileLength; @{"?fqo
} MK(~
} s:3b.*t<
!Ahxi);a
^yX>^1
//启动子线程 [2PPa9F
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; HR;I}J 9
for(int i=0;i<nStartPos.length;i++) _2TL>1KZt
{ 24u_}ZQzY
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), _#qfe
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), ;I?x;lH
nStartPos,nEndPos,i); J7Mbv2D
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); yy Y\g
fileSplitterFetch.start(); O(6j:XD
} Y/sZPG}4
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 03c8VKp'p
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); ~owodc
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", ?,i}Qr [Q
nEndPos = " + nFileLength); >Ptu-*
// fileSplitterFetch[nPos.length-1].start(); qOy0QZ#0
[ ebk u_
pI_dV44W
//等待子线程结束 L{rd',
//int count = 0; W{c Z7$d
//是否结束while循环 GVhy }0|
boolean breakWhile = false; k{H7+;_
z'7XGO'Lo
e/&^~ $h
while(!bStop) E\ls- (,
{ 3m| C8:
write_nPos(); THARr#1b};
Utility.sleep(500); O?O=]s u
breakWhile = true; mVFo2^%v
BOWBD@y
<_c8F!K)T
for(int i=0;i<nStartPos.length;i++) bObsj]
{ Nz}PcWF/
if(!fileSplitterFetch.bDownOver) d^f rKPB
{ *%Fu/
breakWhile = false; %lD+57=
break; txvo7?Y*4
} O4Q"2
} `?O0)
if(breakWhile) 7MGvw-Tpb7
break; qtmKX
3YJ"[$w='(
w2 r
//count++; zez|l
//if(count>4) [N12X7O3
// siteStop(); d&\3}uH
} Z&79: 9=#>
=^SxZ Bn
\2]_NU5.
System.err.println("文件下载结束！"); \Hdsy="Dnh
} lF_"{dS_6(
catch(Exception e){e.printStackTrace ();} -QwH|
} px*1 3"
XDHi4i47`o
050,S`%<g8
//获得文件长度 tHAe
public long getFileSize() L^r & .N\
{ ;s;3cC!
int nFileLength = -1; xW]65iav
try{ a9UXg<4
URL url = new URL(siteInfoBean.getSSiteURL()); kIX1u<M~
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); !JyY&D~`
httpConnection.setRequestProperty("User-Agent","NetFox"); Svb>s|D
tJ 2GSZ`
.`Q^8|$-K
int responseCode=httpConnection.getResponseCode(); tbWfm5$
if(responseCode>=400) {VKFw=$8
{ ]Axz}:
processErrorCode(responseCode); EY:IwDA.}
return -2; //-2 represent access is error *AYq:n6
} ""Da2Md
'_^T]fr}
z:@:B:E
String sHeader; {}$Zff
0|J_'-<
7}g4ePYag
for(int i=1;;i++) |Fi5/$S.
{ TL)*onA9
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); (0B?OkQ
//Utility.log(in.readLine()); DzQ
sHeader=httpConnection.getHeaderFieldKey(i); l#`G4Vf
if(sHeader!=null) #fYB4.i~
{ tc<uS%XT4^
if(sHeader.equals("Content-Length")) 6pSi-FH
{ N0.|Mb"?t
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); 4l+!Z,b
break; R(`:~@3\6
} !?(7g2NP)
} tAF?.\x"g
else #{PwEX !Ct
break; ,zltNbu\.(
} ! 5NuFLOf
} 8AX_y3$
catch(IOException e){e.printStackTrace ();} :nQlS
catch(Exception e){e.printStackTrace ();} ]"lB!O~
7jgj;%
w4vV#C4X
Utility.log(nFileLength); Rd&DH_<+^
_$ivN!k
>WIc"y.
return nFileLength; xbm%+
} ]S%(l,
o87kF!x
%VH,(}i
//保存下载信息（文件指针位置） nuXL{tg6
private void write_nPos() =o~GLbsER
{ sVK?sBs]
try{ +a3E=GJ
output = new DataOutputStream(new FileOutputStream(tmpFile)); > [J.
output.writeInt(nStartPos.length); 8 {V9)U
for(int i=0;i<nStartPos.length;i++) w y|^=#k
{ Q-n8~Ey1a
// output.writeLong(nPos); ;~EQS.Qp
output.writeLong(fileSplitterFetch.nStartPos); d51'[?(
output.writeLong(fileSplitterFetch.nEndPos); Aj)Q#Fd[
} xwf-kwF8^
output.close(); nUOi~cs
} t/\
catch(IOException e){e.printStackTrace ();} ?B1Zfu0
catch(Exception e){e.printStackTrace ();} pA6KiY&
} !g9k9 l
V}Y*Yv
E4L?4>V@\
//读取保存的下载信息（文件指针位置） ]7O<|8n!d
private void read_nPos() W&IG,7tr
{ ?: yz/9(
try{ {aUnOyX_
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); [mA-sl]
int nCount = input.readInt(); A^>@6d $2
nStartPos = new long[nCount]; 3R3H+W0{
nEndPos = new long[nCount]; ~w+I2oS$
for(int i=0;i<nStartPos.length;i++) G aV&y
{ <qwf"Ey
nStartPos = input.readLong(); N2v/<
nEndPos = input.readLong(); wSN9`"
} m$fEk,d
input.close(); cm(*F0<
} C/!.VMl^
catch(IOException e){e.printStackTrace ();} 4|=>gdW)KN
catch(Exception e){e.printStackTrace ();} ?vFy3
} Lwr's'ao.
^_;'9YD
wqb4w7%
private void processErrorCode(int nErrorCode) ^$K&Met
{ Yv5H41o"
System.err.println("Error Code : " + nErrorCode); u4C9ZYN
} U!aM63F3
V4n~Z+k
GtVT^u_
//停止文件下载 H#~gx_^U
public void siteStop() ,~1'L6Ri?
{ L"qJZU
bStop = true; zuV%`n
for(int i=0;i<nStartPos.length;i++) "bm|p/A
fileSplitterFetch.splitterStop(); 2'DCB{Jv
)l7XZ_gw'
;=Ma+d#
} *an Ng<@
} >fH0>W+!
//负责部分文件的抓取 Vr1}Zv3K'
**FileSplitterFetch.java /MGapmqV9
*/ |9#q7kM
package NetFox; {A/r)
EtKq.<SJ
j_~KD}
import java.io.*; 2R[v*i^S
import java.net.*; a!9'yc
b=,BLe\
mn7I# ~
public class FileSplitterFetch extends Thread { R2,9%!iiX
m+<&NDj.
2n:<F9^"
String sURL; //File URL x]{P.7IO'
long nStartPos; //File Snippet Start Position Mg;pNK\n
long nEndPos; //File Snippet End Position E#$Jg|e
int nThreadID; //Thread's ID Vu:ZG*^
boolean bDownOver = false; //Downing is over Q$E.G63Wl
boolean bStop = false; //Stop identical [';o -c"!
FileAccessI fileAccessI = null; //File Access interface hdPGqJE
%Mda<3P
(S~kyU!)0
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException cx\E40WD
{ qGk.7wf%
this.sURL = sURL; nTeA=0 4
this.nStartPos = nStart; @dWA1tM
this.nEndPos = nEnd; l<v{8:,e#
nThreadID = id; JQV%W+-@
fileAccessI = new FileAccessI(sName,nStartPos);//定位 \'m7un
} iWs6 !s!
Kh]es,$D
#a e@VedM
public void run() q+?&w'8
{ WqeWjI.2
while(nStartPos < nEndPos && !bStop) /Q1 b%C
{ _3`GZeGV
%;[DMc/
*k{Llq
try{ h`&TDB2
URL url = new URL(sURL); Kxsd@^E
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); MntmBj-T
httpConnection.setRequestProperty("User-Agent","NetFox"); SZWNN#w60?
String sProperty = "bytes="+nStartPos+"-"; )Te\6qM
httpConnection.setRequestProperty("RANGE",sProperty); ~7:q+\
Utility.log(sProperty); `<YMkp[
QVT0.GzR
G\sx'#Whc
InputStream input = httpConnection.getInputStream(); w <r*&
//logResponseHead(httpConnection); +(+lbCW/
xV> .]
Xf4QLw/r
byte[] b = new byte[1024]; /!]K+6>u
int nRead; 7X$CJ%6b
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) iC#a+G*N_M
{ '.v;/[0
nStartPos += fileAccessI.write(b,0,nRead); -H60T,o
//if(nThreadID == 1) iJ{axa &
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); ]&8em1
} 3r~8:F"g
(JbRhcg
+6WjOcu
Utility.log("Thread " + nThreadID + " is over!"); dn h qg3Y
bDownOver = true; .\b.l@O<Z
//nPos = fileAccessI.write (b,0,nRead); b `P6Ox3
} jJ2rfdfj
catch(Exception e){e.printStackTrace ();} 6()Jx%
} !X}+JeU'
} MT{1/A;`)
*).
z 0?MeH#
//打印回应的头信息 [J2evi?
public void logResponseHead(HttpURLConnection con) >!fTWdD^
{ `{#""I^_
for(int i=1;;i++) |j+JLB
{ dpW`e>o
String header=con.getHeaderFieldKey(i); upMs yLp(
if(header!=null) s)\PY
//responseHeaders.put(header,httpConnection.getHeaderField(header)); 4-bM90&1t
Utility.log(header+" : "+con.getHeaderField(header)); eEqcAUn
else 0*MUe1{
break; w"v96%"Y
} 8(? &=>@
} {L$$"r,
dw6ysOR@
zTue(Kr
public void splitterStop() nk!uO^
{ 6PsT])*>DE
bStop = true; xhALJfv
} 5YrzOqg=
\(??Ytc<B
*L<EGFP
} f#c}}>V8
6GuTd
MgiW9@_(
/* CV[9i
**FileAccess.java J{4=:feIC?
*//文件访问(定位，写) ZKI8x1>Iq
package NetFox; K-'uE)
import java.io.*; 4l0>['K&{
W(62.3d~}?
%|4Kak]:Q
public class FileAccessI implements Serializable{ Lum=5zDo
1!zd#TX
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 )7NK+k
RandomAccessFile oSavedFile; VK/L}^=GOO
long nPos; U9BhtmY
c6jVx_tt.
`"~GqFwy~
public FileAccessI() throws IOException |ghyH
{ KEy8EB
this("",0); 2?qT,pN
} W /v &V#
0<V/[$}\D
]R~hzo
public FileAccessI(String sName,long nPos) throws IOException V1,p<>9
{ yFm88
oSavedFile = new RandomAccessFile(sName,"rw"); [m! P(o
this.nPos = nPos; e>_a (
oSavedFile.seek(nPos); sC"w{_D@*4
} 6# bTlmcg
otaRA
zZd.U\"2
public synchronized int write(byte[] b,int nStart,int nLen) _k}Qe;
{ #bcZ:D@FC
int n = -1; 0[H/>%3O
try{ `)$G}7cRUH
oSavedFile.write(b,nStart,nLen); P*[wB_^&UP
n = nLen; E;H9]*x/
} pa^_D~
catch(IOException e) H{*rV>%
{ SDbkPx
e.printStackTrace (); me@`;Q3
} SP<(24zdd
IPTFx )]G
`#ff`j|a
return n; jBEW("4R
} o]I8Ghk>/z
vMY!Z1.*
CY=lN5!J
} I\Y N!
KO`dAB F}
Ze/\IBd
/* \R9izuc9
**SiteInfoBean.java [zl4"|_`
*/ 'Jek< 5
package NetFox; CY':'aWfa<
X
Y4N7# 5
public class SiteInfoBean { 60n>FQ<
2WLLI8
nWc@ufY
private String sSiteURL; //Site's URL eKuF7Oo
private String sFilePath; //Saved File's Path Sz|kXk6&9
private String sFileName; //Saved File's Name p5"pQeS
private int nSplitter; //Count of Splited Downloading File %Cj_z
`'3&tAy
w)&4i$Lk6
public SiteInfoBean() eU)QoVt
{//nSplitter的缺省值为5 Txl|F\nK`
//default value of nSplitter is 5 ;Y8>?
this("","","",5); #I MaN%
} v2r|)c,h
wQ/.3V[
z&c}
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) Qe!3ae`Z
{ ?v:FGO
sSiteURL= sURL; FzSL[S4i
sFilePath = sPath; Oc,HnyV+
sFileName = sName; .*n*eeD,
this.nSplitter = nSpiltter; 2rC&
E 6MeM'sx
J8@.qC'!
} I5QtPqB>
ue?3;BF 5
a>-qHX-l
public String getSSiteURL() 0t(c84o5
{ _Wk*h}x
return sSiteURL; SXe1Q8;
} __+8wC
<_kA+&T
MSBrI3MqQ
public void setSSiteURL(String value) mJ(ElDG
{ 7;Lv_Y"b
sSiteURL = value; pUqNB_
} g'w"U9tjO
"1XTgCu\
)/[L)-~y~
public String getSFilePath() XM"Qs.E
{ G=gU|& (
return sFilePath; }/\`'LQ
} \ntUxPox.
[n&ES\o#(
2wPc yD
public void setSFilePath(String value) \M|:EG%
{ G; exH$y
sFilePath = value; *"Iz)Xzc`
} D vU1+y
Z5F#r>>`
a[z$ae7
public String getSFileName() LXJ;8uW2y
{ 9@IL547V
return sFileName; NX8hFwR
} WI*CuJU<zJ
vf#d
dIh+h|:
public void setSFileName(String value) bZAL~z+ V
{ IsJx5GO
sFileName = value; PJ?C[+&
} (C uM*-
XHdhSFpm
f[R~oc5P0
public int getNSplitter() bWlYQ
{ _!vy|,w@e
return nSplitter; =-r); d
} y3j"vKG
d-m.aP)y:
ux!YVvTPd
public void setNSplitter(int nCount) |& jrU-(
{ <I2ENo5?
nSplitter = nCount; &%@O V:C
} G3]#Du
} Nmt~1.J
5a@9PX^.J
~Mar
/* .m\0<8C
**Utility.java Wb cm1I)
*/ <Uj9~yVN]
package NetFox; X6(s][Wn
\G)F*
":s_O.
public class Utility { WcM\4q@
>KdV]!H
);q~TZ[Do
public Utility() .oLV\'HAR
{ W[j,QU
rev*G:
%yjD<2J;
} v[8+fd)}S
T2.[iD!A
//线程睡眠 ITn PF{N
public static void sleep(int nSecond) 3Z me?o*bY
{ f{[0;qDJ
try{ liLhvcd
Thread.sleep(nSecond); %m[ZU<v
} FINHO058^Y
catch(Exception e) PXJ7Ek*/
{ WK7?~R%rq
e.printStackTrace (); 7OG:G z+)x
} gGMQRRq
} s0D4K
k 9z9{
//日志 XQfmD;U
public static void log(String sMsg) -}h^'#
{ d}ycC.h4k
System.err.println(sMsg); ~Fwbi
} Sl^PELU
ZE_
hLk6Hqr7
public static void log(int sMsg) %OO}0OW
{ mb1c9
System.err.println(sMsg); V?wV*]c
} 3b]M\F9
} R)\^*tkz7
BbCO K
woPj>M
/* Za3}:7`Gu
**TestMethod.java BL_0@<1X
*/ /T(9:1/G
package NetFox; > l0H)W
Qs59IZ
gOW8!\V
public class TestMethod { Hk h'h"_r
&{+0a[rN
y5+%8#3
public TestMethod() {Y Y,{H
{ ///xx/weblogic60b2_win.exe E0&d*BI2
try{ fbbbTZy
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); Dat',5
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); k>.8lc\
SiteFileFetch fileFetch = new SiteFileFetch(bean); PcU~1m1
fileFetch.start(); 0('ec60u
} ?8GS*I
catch(Exception e){e.printStackTrace ();} HDZl;=
Iapz,nuE
~eoM 2XlW
} <9yh:1"X
u{\'/c7G
S5y.H
public static void main(String[] args) zhFm2
{ fbOqxF"?we
new TestMethod(); )=29Hm"
} rZaO^}u]
} fC*cqc~{@
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