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)); &>Ko}?w
} VgSk\:t
for(int i=0;i<nEndPos.length-1;i++) !/},k"p6
{ ^uy2qO4Yw
nEndPos = nStartPos[i+1]; 9b0M'x'W5
} oo:(GfO}
nEndPos[nEndPos.length-1] = nFileLength; WG_20JdJY
} g7|$JevR0
} l5m5H,`
aC&ZV}8of
l^F%fIRp)
//启动子线程 *FwHZZ~U
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; ZL-YoMHc+_
for(int i=0;i<nStartPos.length;i++) l{{wrU`
{ {c3u!}mW
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), nA\9UD<G.
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), W:8*Z8?7
nStartPos,nEndPos,i); n tfwR#j
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); .o2]ndT/J
fileSplitterFetch.start(); nVTCbV
} b$24${*'
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), WG{mg/\2(C
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); ;gh#8JkI
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", yvgn}F{}
nEndPos = " + nFileLength); -bamNw>|
// fileSplitterFetch[nPos.length-1].start(); e*Gm()Vu,
}^Unx W
~9:ILCfX
//等待子线程结束 ;9{x""
//int count = 0; oH/4opV
//是否结束while循环 ">n38:?R
boolean breakWhile = false; 5K;vdwSB
uh~/ybR
[\M=w7
while(!bStop) GnE%C2L-
{ #nE%.k|R~
write_nPos(); )TceNH
Utility.sleep(500); ; )Vro
breakWhile = true; 7-oH >OF^
JeR8Mb
brkR,(#L3
for(int i=0;i<nStartPos.length;i++) iI[Z|"a21
{ ZD9UE3-
if(!fileSplitterFetch.bDownOver) U8Pnt|0M
{ H?M#7K~[
breakWhile = false; C*}TY)8
break; %`%xD>![
} 8?GS:+
} rAdYBr=0
if(breakWhile) fq){?hk~O
break; M-!eL<
A2o;YyF
`L(AvSR
//count++; g8yWFqE!T
//if(count>4) kO:iA0KUX
// siteStop(); w#Y<~W&
} 8cm,G
[?<"SJ,`
G .~Psw#
System.err.println("文件下载结束！"); |H.(?!nTb
} GNXQD}L?b?
catch(Exception e){e.printStackTrace ();} ?Uzs^rsb
} uc?QS~H&w
f[n#Eu}
X[8m76/V
//获得文件长度 (lhbH]I
public long getFileSize() {m9OgR5U
{ }Po&6^
int nFileLength = -1; b|T}mn
try{ "t+VF4r
URL url = new URL(siteInfoBean.getSSiteURL()); G3P3
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); (=${@=!z
httpConnection.setRequestProperty("User-Agent","NetFox"); ,jyNV<dI
3LZ0EYVL
XF1x*zc
int responseCode=httpConnection.getResponseCode(); XljiK8q;%
if(responseCode>=400) 8jxgSB",
{ WlVC0&
processErrorCode(responseCode); QQKvy0?1
return -2; //-2 represent access is error M:c^[9)y
} 0@E[IDmp
7-+X -Y?
5gg_c?Vh/
String sHeader; B`a5%asJn
lhAwTOn`Q
-^8gZk/(W
for(int i=1;;i++) MpM-xz~
{ -IJt( X|
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); qFmvc
//Utility.log(in.readLine()); KcVCA
sHeader=httpConnection.getHeaderFieldKey(i); 4E:HO\
if(sHeader!=null) p"/1Kwqx
{ OWCd$c_(
if(sHeader.equals("Content-Length")) E9{Gaa/{
{ .eW}@1+[;
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); %;9f$:U
break; G*e/Ft.wf8
} +Ij>\;vM"
} .l5y!?
else Zb`}/%\7
break; pL>Q'{7s3
} kRnh20I
} +L*2 6ar6
catch(IOException e){e.printStackTrace ();} M)6_Tal
catch(Exception e){e.printStackTrace ();} GAbX.9[V
noa?p&Y1m
2}1(j
Utility.log(nFileLength); i NzoDmE*
@!^c@
q~.\NKc
return nFileLength; _h7!
} .Xh^L
\?h +
/iNCb&[
//保存下载信息（文件指针位置） #ldNWwvRGj
private void write_nPos() 0)-l9V
{ ^~|P[}
try{ S0 M-$
output = new DataOutputStream(new FileOutputStream(tmpFile)); a3ve%b
output.writeInt(nStartPos.length); dx}()i\@
for(int i=0;i<nStartPos.length;i++) l%.3hId-
{ ):jKsP ,
// output.writeLong(nPos); =(K;z9OR
output.writeLong(fileSplitterFetch.nStartPos); ho ?.\Jq
output.writeLong(fileSplitterFetch.nEndPos); EbuOPa
} ^%|{>Mz;c
output.close(); Lo @mQ
} lQ!ukl)
catch(IOException e){e.printStackTrace ();} ZU7e1VaZM
catch(Exception e){e.printStackTrace ();} yC4JYF]JN
} o\1"ux;b
*-T3'beg
. [+ObF9=
//读取保存的下载信息（文件指针位置） KWCA9.w4q
private void read_nPos() YN9ug3O+
{ v-Ggf0RF
try{ T/MbEqAf
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); 1\{0z3P
int nCount = input.readInt(); #*j
nStartPos = new long[nCount]; 1C^6'9o
nEndPos = new long[nCount]; DY^q_+[V
for(int i=0;i<nStartPos.length;i++) jY$Bns&.w
{ :e ?qm7cB
nStartPos = input.readLong(); [zn`vT
nEndPos = input.readLong(); ,'m<um
} 0!o&=Qh
input.close(); cgc|G
} "]JE]n}Ulg
catch(IOException e){e.printStackTrace ();} fOm=#:O
catch(Exception e){e.printStackTrace ();} ?o$6w(]''
} (ScL C
Uc!}D
"X's>uM
private void processErrorCode(int nErrorCode) [IF3,C
{ Ti#2D3
System.err.println("Error Code : " + nErrorCode); #q9jFW8
} &48wa^d
bk}.^m!
Dsw(ti`@
//停止文件下载 ^, q\S
public void siteStop() .AH#D}m
{ ]MfT5#(6h
bStop = true; }ARWR.7Cc
for(int i=0;i<nStartPos.length;i++) tmDI2Z%7
fileSplitterFetch.splitterStop(); ~ULuX"n
K:c5Yq^
:@KWp{ D7
} _S{HVc
} -i:Zi}f
//负责部分文件的抓取 Uxn_nh
**FileSplitterFetch.java m!er"0
*/ ea3AcT6
package NetFox; aDm$^yP
*$Aneq0f
j0>S)Q
import java.io.*; k+5:fB)z
import java.net.*; J)oa:Q
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wWko9h=|mQ
public class FileSplitterFetch extends Thread { "KcSOjvJ
rOm)s'
2shr&Mfp[
String sURL; //File URL UN'hnqC
long nStartPos; //File Snippet Start Position cAM1\3HWT"
long nEndPos; //File Snippet End Position 1t+]r:{
int nThreadID; //Thread's ID Jt43+]
boolean bDownOver = false; //Downing is over 'C]zB'H=
boolean bStop = false; //Stop identical aAh")B2
FileAccessI fileAccessI = null; //File Access interface <8|vj2d2
-A(]",*J
bqJL@!T
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException ^6Q(he
{ f]^(|*6
this.sURL = sURL; y>'^<xk
this.nStartPos = nStart; %0YwaxXPn7
this.nEndPos = nEnd; #.$p7]
nThreadID = id; _&FcHwRy
fileAccessI = new FileAccessI(sName,nStartPos);//定位 Qf6]qJa|
} E}-Y@( [
/(8Usu?g.
+_|M*%
public void run() "[L[*>[9!
{ yBXdj`bV
while(nStartPos < nEndPos && !bStop) B'"C?d<7
{ SouPk/-B80
k?0yH$)'t
.e!dEF)D
try{ - U!:.
URL url = new URL(sURL); @QV|<NeH
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); JBtcl#|
httpConnection.setRequestProperty("User-Agent","NetFox"); F8$.K*tT
String sProperty = "bytes="+nStartPos+"-"; K{B[(](
httpConnection.setRequestProperty("RANGE",sProperty); k {_X%H/
Utility.log(sProperty); sn '#]yM
}o0R`15dA
j#$ R.
InputStream input = httpConnection.getInputStream(); tH,}_Bp
//logResponseHead(httpConnection); zGHP{a1O7
DlC`GZEtqh
U=\ZeYK.
byte[] b = new byte[1024]; dqwAQ-x
int nRead; c}kZx1
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) R(@B4M2
{ }OZ%U2PU
nStartPos += fileAccessI.write(b,0,nRead); aFjcyD
//if(nThreadID == 1) v: cO+dQ
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); bccJVwXv
} ;:,hdFap
|'9%vtbM
lCLz!k2di
Utility.log("Thread " + nThreadID + " is over!"); N`1:U 4}
bDownOver = true; 9G_bM(q'^2
//nPos = fileAccessI.write (b,0,nRead); L}UJ`U
} /.9j$iK#
catch(Exception e){e.printStackTrace ();} +ObP[F
} 6+u}'mSj8
} }J73{
Gl}[1<~o
eu@hmR8T
//打印回应的头信息 td%]l1
public void logResponseHead(HttpURLConnection con) |b7v(Hx
{ `[3Iz$K=
for(int i=1;;i++) fw$/@31AP?
{ 3/>T/To&2
String header=con.getHeaderFieldKey(i); 9\ZlRYnc=
if(header!=null) &b8Dy=#
//responseHeaders.put(header,httpConnection.getHeaderField(header)); nAPSs]D
Utility.log(header+" : "+con.getHeaderField(header)); f2ygN6(>
else Aw9se"d
break; @8E mY,{;
} =cI -<0QSn
} Tj7OV}:
E/2kX3}
^ cpQ*Fz
public void splitterStop() Dg3Sn|!f
{ !2R~/Rg
bStop = true; Sm(X/P=z
} Bd jo3eX
4XpW#>
R#gt~]x6k
} $*w]]b$Dn
-x)Oo`
q}P< Ejq}
/* DuX7
**FileAccess.java ,rj_P
*//文件访问(定位，写) %EkV-%o*
package NetFox; hr3RC+ y
import java.io.*; 6-#<*Pg
tS#=I.ET
nAIV]9RAZ%
public class FileAccessI implements Serializable{ $I*ye+a*{q
j_H"m R
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 8CCd6)cG
RandomAccessFile oSavedFile; ERD( qL.J
long nPos; 7i^7sT8t
K8`Jl=}z%&
sjl(
public FileAccessI() throws IOException Xq:jp+WSG
{ Nfe
this("",0); _+Tq&,_:o
} .m%/JquMFM
U8TH}9Q
}]O* yFR{j
public FileAccessI(String sName,long nPos) throws IOException fLkZ'~e!
{ tuH8!.
oSavedFile = new RandomAccessFile(sName,"rw"); #9{N[t
this.nPos = nPos; -M=#U\D
oSavedFile.seek(nPos); ,36AR|IO)
} .U}"ONd9e
u /PaXQ
@c3GJ'"X
public synchronized int write(byte[] b,int nStart,int nLen) DD 8uG`<
{ Cka&b
int n = -1; i,#j@R@.C7
try{ #?=?<"*j
oSavedFile.write(b,nStart,nLen); 8{DZew /
n = nLen; ;QYUiR
} Iw@ou
catch(IOException e) "rxhS; R1>
{ +5:Dy,F=
e.printStackTrace (); >4I,9TO
} poLzgd
+=.>9
,Sz`$'^c
return n; IQz"FH?
} t<8vgdD
`Wc"Ix0
Ug :3)q[O
} etnq{tE5
;/-v4
7kiZFHV
/* ^:krfXT
**SiteInfoBean.java ~yX8p7qr
*/ p2m@0ou
package NetFox; eXs^YPi
\!-IY
`.oWmBey\
public class SiteInfoBean { _xKuEU}
^Om0~)"q
a7$]" T 7
private String sSiteURL; //Site's URL JAt$WW{
private String sFilePath; //Saved File's Path &#[w*t(A
private String sFileName; //Saved File's Name m-xnbTcQ
private int nSplitter; //Count of Splited Downloading File xi+bBqg<.K
X283.?
R_DstpsT
public SiteInfoBean() ot%^FvQ[c
{//nSplitter的缺省值为5 2wCSjAWWh(
//default value of nSplitter is 5 Gy;>.:n
this("","","",5); #'5C*RO
} 8-JOfq}s
!xE/
3t4i2]
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) =D>,s)}o3;
{ c[IT?6J4
sSiteURL= sURL; Etj0k} A
sFilePath = sPath; E{wnhsl{
sFileName = sName; ^uWPbW&/q
this.nSplitter = nSpiltter; z`Jcpt
|]M|IX8 o
,H)v+lI
} }]<Ghns
]2_b_ok
&g;&=<#I
public String getSSiteURL() (yJY/|
{ 04j]W]8#
return sSiteURL; '!hA!eo>J
} `i2:@?Kl9
" jBc5*
7^oO N+=d
public void setSSiteURL(String value) h&|S*
{ DXa!"ZU
sSiteURL = value; o){\qhLp
} a23XrX
XfYbWR
sk%Xf,
public String getSFilePath() R9&3QRW|
{ [yhK4A
return sFilePath; Bs3M7zRG
} {i^F4A@=Z
d}w}VL8l
<G_71J`MLC
public void setSFilePath(String value) U[R[VY7
{ 2JhE`EVH
sFilePath = value; `DFo:w!k
} h(/& ;\Cr
0'ge}2^
=j"bLX6;
public String getSFileName() ?8/T#ox
{ 3sK^ (
return sFileName; 5-RA<d#
} .WVIdVO7
hDf!l$e.
h J H
public void setSFileName(String value) 96d&vm~m1
{ so>jz@!EE
sFileName = value; tuslkOE#
} rU |%
re xMS
m7|S'{+!
public int getNSplitter() [y&uc
{ rNoCmNm
return nSplitter; iOB*K)U1
} |vPU]R>6
A D%9;KQ8
[85b+SKW
public void setNSplitter(int nCount) bcYGkvGbO
{ :I2spBx
nSplitter = nCount; (5l'?7
} o&)v{q
} w&>*4=^a
.^wBv 'Y
_/NPXDL
/* *pYawT
**Utility.java 0C4Os p
*/ L>n^Q:M
package NetFox; T[- %b9h>
q\/xx`L
.umN>/o[
public class Utility { ge]Z5E(1
~cf)wrP
a/n~#5-
public Utility() `0`#Uf_/$
{ -FS!v^
bQ-n<Lx
l% p4.CX
} R(s[JH(&
sWKv>bx
//线程睡眠 %3yrX>Js
public static void sleep(int nSecond) 63'L58O
{ j>3Fwg9V
try{ XEUS)X)
Thread.sleep(nSecond); l%qfaU2
} R@KWiV
catch(Exception e) mr,GHx
{ I:WPP'L4o
e.printStackTrace (); #!>`$
} F(`Q62o@
} @9lGU#
"?6R"Vk?:
//日志 iV:\,<8d
public static void log(String sMsg) CoV@{Pi
{ Yc5<Y-W
System.err.println(sMsg); }tJMnq/m($
} -|P7e
MfraTUxIo/
@ev^e!B
public static void log(int sMsg) q)PSHr=Z
{ I*KJq?R
System.err.println(sMsg); #fFD|q
} z=4E#y`?U
} @"iNjqxh
PPh1y;D
)O\l3h"
/* xOZvQ\%
**TestMethod.java &<) _7?
*/ )+.AgqxI
package NetFox; Cyud)BZvm
y*8;T v|
BbI),iP
public class TestMethod { lEpPi@2PK
yCv"(fNQ
7KtgR=-Lb
public TestMethod() 3ep L'My$
{ ///xx/weblogic60b2_win.exe F|&mxsL
try{ VKi3z%kwK
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); *T{KpiuP
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); R~bLEo
SiteFileFetch fileFetch = new SiteFileFetch(bean); ik0w\*
fileFetch.start(); l4OPzNc'
} wDs#1`uTq
catch(Exception e){e.printStackTrace ();} }Ub "Vb
6uFGq)4p@
JM*rPzp
} *oIKddZh
v=H!Y";
@T-}\AU
public static void main(String[] args) Q1 vse
{ Bc#6mO-
new TestMethod(); w2tkJcQ3
} 16I(S
} B^1Io9
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