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)); %EYh5W
} k:nR'TI
for(int i=0;i<nEndPos.length-1;i++) "q(#,,_
{ PW"G]G,
nEndPos = nStartPos[i+1]; 'v.i' 6
} . KJEA#
nEndPos[nEndPos.length-1] = nFileLength; UH1AT#?!W
} @~0kSA7
} 9"g=it2Rh6
,vEwck#
&B\tcF
//启动子线程 > $0eRVL
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; "ZDc$v:Qa
for(int i=0;i<nStartPos.length;i++) N.OC _H&
{ wkK61ah6
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 0[@9f1Nk4
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), c#M'Mye
nStartPos,nEndPos,i); (.,`<rXw
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); cQ~}qE>I
fileSplitterFetch.start(); f?T6Ne'
} h4x*C=?A
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), E(A7DXzbR
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); mw9;LNi\D
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", z5PFppSQ
nEndPos = " + nFileLength); OJng
// fileSplitterFetch[nPos.length-1].start(); S?Q4u!FC
S+>1yvr),
Bi9b"*LN
//等待子线程结束 R9Wh/@J]
//int count = 0; 5;5;bBo~
//是否结束while循环 $F-qqkR$
boolean breakWhile = false; _IJPZ'Hr
Q6Z%T.1
w4U]lg<}E
while(!bStop) 7Wb:^.d g
{ ,Ju f
write_nPos(); qepsR/0M
Utility.sleep(500); l$D]*_ jc,
breakWhile = true; EotZ$O=
:nYl]Rm
:Xc%_&)
for(int i=0;i<nStartPos.length;i++) %;kr%%t%
{ )NJD+yQ%
if(!fileSplitterFetch.bDownOver) z5-vx`
{ R,CFU l7Q
breakWhile = false; jPg8>Z&D
break; EzOO6
} 2@ vSe
} -M}#-qwf
if(breakWhile) cUssF%ud]
break; ]YQ[ )
zRPXmu{t
vwDnz/-
//count++; k`Nc<nN8
//if(count>4) l`8S1~j
// siteStop(); 1a4HThDXP
} ?ihkV?;)
'"LrGvkZ
bFk >IifN
System.err.println("文件下载结束！"); n5dFp%k
} @0A7d $J(
catch(Exception e){e.printStackTrace ();} @mBZu!,
} N*w/\|
kFmd):U!R
%7 h_D
//获得文件长度 <CIJg*
public long getFileSize() ko\VDyt,
{ s@sRdoTdF
int nFileLength = -1; k"F5'Od
try{ b=v
URL url = new URL(siteInfoBean.getSSiteURL()); ^Ts|/+}'i
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); o5KpiibFM
httpConnection.setRequestProperty("User-Agent","NetFox"); 57IAH$n8o
3RG*:9
ocBfs^ aW
int responseCode=httpConnection.getResponseCode(); f$$l,wo
if(responseCode>=400) :&ir5xHS
{ E>f+E8?
processErrorCode(responseCode); B9pro%R1Bo
return -2; //-2 represent access is error j+AAhn
} n;8[WR)
U<J4\|1?7'
fCTdM+t
String sHeader; (&R/ns~
HbQ `b
NXsDn&&O
for(int i=1;;i++) 3jQy"9f
{ Sc'z vlq
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); :xISS
//Utility.log(in.readLine()); (#GOXz
sHeader=httpConnection.getHeaderFieldKey(i); OW1i{
if(sHeader!=null) I\E`xkbBu
{ !Kr|04Qp#x
if(sHeader.equals("Content-Length")) <6g{vNA
{ NNSHA'F,.\
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); C o v,#j j
break; [sJ f)<
} P3X;&iT
} O?e38(
else %LeG.~?
break; $,$bZV
} K|nh`r
} =TKu2
catch(IOException e){e.printStackTrace ();} yq+'O&+
catch(Exception e){e.printStackTrace ();} bb}zn'xC
0zfh:O
ek!x:G$'
Utility.log(nFileLength); N9hs<b+N_
7l}P!xa&
P6'Oe|+'
return nFileLength; 0o~? ]C
} KDr?<"2L
9TRS#iVL+*
%suSZw`
//保存下载信息（文件指针位置） 6L[Yn?;
private void write_nPos() u;p.:{'
{ o))z8n?b
try{ m "'
output = new DataOutputStream(new FileOutputStream(tmpFile)); d_s=5+Yj
output.writeInt(nStartPos.length); L+,p#w
for(int i=0;i<nStartPos.length;i++) %+gYZv-
{ =Hplg>h)
// output.writeLong(nPos); AsJN~<0h
output.writeLong(fileSplitterFetch.nStartPos); I3`WY-uv
output.writeLong(fileSplitterFetch.nEndPos); 5%,5Xe4p
} E~vM$$O$
output.close(); tY~gn|M
} .vsrZ_y?
catch(IOException e){e.printStackTrace ();} o1C1F}gxU
catch(Exception e){e.printStackTrace ();} QND{3Q
} 5(RFkZn4[
jMv qKJ(<
-|;{/ s5
//读取保存的下载信息（文件指针位置） -xs@rV`
private void read_nPos() q5C(/@)^
{ 0Oy.&C T
try{ |Iei!jm
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); x=>B 6o-f
int nCount = input.readInt(); ybLl[K(D=
nStartPos = new long[nCount]; 2F*spu
nEndPos = new long[nCount]; 278:5yC
for(int i=0;i<nStartPos.length;i++) kN(*.Q|VZ
{ o2M+=O@
nStartPos = input.readLong(); ~ 8L]!OQ9=
nEndPos = input.readLong(); T DOOq;+
} k4:$LFw@
input.close(); K|JpkEw
} U-~cVk+LI
catch(IOException e){e.printStackTrace ();} 52Sq;X
catch(Exception e){e.printStackTrace ();} N$>.V7H&
} $yxwB/O(
3 RB+
.j"iJ/
private void processErrorCode(int nErrorCode) /+^7lQo\]
{ /}+VH_N1
System.err.println("Error Code : " + nErrorCode); \Ps}1)wT
} UrtA]pc3L
8@;|x2=y
ptJ58U$Bb
//停止文件下载 sa8JN.B
public void siteStop() +tOmKY
{ j9Qd 45
bStop = true; `pr$l
for(int i=0;i<nStartPos.length;i++) 7#/->Y
fileSplitterFetch.splitterStop(); a#3+PB#
Ws;S=|9,7~
='r86vq
} wW2b?b{*Z
} "&h{+DHS
//负责部分文件的抓取 co!o+jP
**FileSplitterFetch.java s<3cvF<
*/ Hq<Sg4nz
package NetFox; SURbH;[
9*s''=
dH]0(aJ
import java.io.*; Z;M}.'BE
import java.net.*; FuqMT`
{qxFRi#\k
WX.6|
public class FileSplitterFetch extends Thread { QuFzj`(
akR+QZ,)
9*fA:*T
String sURL; //File URL q!UN<+k\h
long nStartPos; //File Snippet Start Position =NJ:%kvF
long nEndPos; //File Snippet End Position z!`aJE/
int nThreadID; //Thread's ID I*h%e,yIO
boolean bDownOver = false; //Downing is over $D;/b+a
boolean bStop = false; //Stop identical n^}M*#
FileAccessI fileAccessI = null; //File Access interface a'zXLlXgGd
@4sEHk 3
R<\5q%@G
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException HJ5 Ktt
{ KDTG9KC
this.sURL = sURL; * AsILK0
this.nStartPos = nStart; ~|y$^qy?U
this.nEndPos = nEnd; W`^euBr7R>
nThreadID = id; ad <z+a
fileAccessI = new FileAccessI(sName,nStartPos);//定位 dU4 h
} 9gWR djK:
pI>yO~Ve
{B;<R1
public void run() tjONN(K`
{ 3K)12x$.K
while(nStartPos < nEndPos && !bStop) (29h{=P'
{ qH1k
a4a/]q4T
<]:X
try{ ,[gu7z^|
URL url = new URL(sURL); %IAZU c
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); k[_)5@2
httpConnection.setRequestProperty("User-Agent","NetFox"); vI84=n
String sProperty = "bytes="+nStartPos+"-"; W~" 'a9H/
httpConnection.setRequestProperty("RANGE",sProperty); gteG*pi
Utility.log(sProperty); 8]G
U2hPsF4f
#:q$sKQ_$
InputStream input = httpConnection.getInputStream(); whH_<@!
//logResponseHead(httpConnection); JXT%@w>I
Z}X oWT2f
pt/UY<@yoN
byte[] b = new byte[1024]; /Kw}R5l
int nRead; Kp]\r-5UD>
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) z2.9l?"rfQ
{ .8.4!6~@
nStartPos += fileAccessI.write(b,0,nRead); Ai*R%#
//if(nThreadID == 1) ^4G%*-
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); G`;YB
} Pn?,56SD=
kdq<)>"
cA,`!dG2,
Utility.log("Thread " + nThreadID + " is over!"); +ConK>;
bDownOver = true; &XvSAw+D@
//nPos = fileAccessI.write (b,0,nRead); @%FLT6MY
} Q4;%[7LU
catch(Exception e){e.printStackTrace ();} T O]wD^`
} OV~]-5gau
} tVUC@M>'
<bvbfS
4z;@1nN_8a
//打印回应的头信息 \zx &5a #
public void logResponseHead(HttpURLConnection con) ~]w|ULNa3|
{ yuef84~
for(int i=1;;i++) E%.w6-
{ i(Xz3L#(
String header=con.getHeaderFieldKey(i); v0aV>-v
if(header!=null) H\>0jr`
//responseHeaders.put(header,httpConnection.getHeaderField(header)); rd )_*{
Utility.log(header+" : "+con.getHeaderField(header)); yG v7^d
else 5YV3pFz$)
break; vk1E!T9X
} B@+&?%ub:
} /r8'stRzv
og?>Q i Tr
#7*{ $v
public void splitterStop() $.5f-vQp
{ c4Leh"ry
bStop = true; ~[N"Q|D3Y
} B2kKEMdGg
$>M-oNeC
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} ,P>xpfdK
xj!G9x<!
dvc=<!"'S
/* vvi[+$M
**FileAccess.java @$*LU:[
*//文件访问(定位，写) &s{" Vc9]
package NetFox; yIq. m=
import java.io.*; %"jp':
[X&VxTxr
4Ou5Vp&y
public class FileAccessI implements Serializable{ w7d<Ky_C
o9XT_!Cwg
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 ! ^ DQX=1
RandomAccessFile oSavedFile; id?B<OM
long nPos; W'xJh0o
#Fwf]{J
*.,G;EC^
public FileAccessI() throws IOException pYBY"r
{ c e\|eN[
this("",0); llE_-M2gH
} P}re"<MD
L|`(u
x & ZW f?
public FileAccessI(String sName,long nPos) throws IOException 0XzrzT"&
{ O;6am++M@
oSavedFile = new RandomAccessFile(sName,"rw"); qib4DT$v-6
this.nPos = nPos; _!ITCkBj
oSavedFile.seek(nPos); W1!Nq`
} j*fs [4
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[-p?gyl
public synchronized int write(byte[] b,int nStart,int nLen) Z(|'zAb^
{ 3 q^^Os
int n = -1; X+%5q =N
try{ s[n*fV']A
oSavedFile.write(b,nStart,nLen); K\VL[HP-
n = nLen; wfMtWXd;KB
} ]n 'FD|
catch(IOException e) L5RBe
{ 1 k\~%
e.printStackTrace (); uLq%Nu
} S2\|bs7;J,
%2ZWSQD
[dIlt"2fV
return n; *RllKPY)
} KB5<)[bs
9`FPV`/
t,IQ|B&0
} -L6V)aK&
Q13>z%Rge
^V?W'~
/* 0K:3?Ik
**SiteInfoBean.java "/g\?Nce
*/ DlF6tcoI
package NetFox; 8`Iz%rw&(J
KM9)
$gPR3*0
public class SiteInfoBean { ',l}$]y5
iebnQf
-RBH5+SS2
private String sSiteURL; //Site's URL vwIP8z~<
private String sFilePath; //Saved File's Path +\s&v!
private String sFileName; //Saved File's Name cKe{ ]a
private int nSplitter; //Count of Splited Downloading File ZD#{h J-
QT)5-Jy
1=Y pNXX
public SiteInfoBean() Z[%vO?,
{//nSplitter的缺省值为5 wqE+hKs,
//default value of nSplitter is 5 _!C M
this("","","",5); ;hZ^zL
} x*a^msY%
7\<}378/^
HlgkW&}c^
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) @3Nvf}He
{ f}ES8Hh[
sSiteURL= sURL; 8h$f6JE
sFilePath = sPath; &Ndq^!e
sFileName = sName; kNC]q,ljt5
this.nSplitter = nSpiltter; aQ#6PO7.Z
{Q/_I@m].
EF5:$#
} X775j"<d
i"GCm`
9*CJWS;
public String getSSiteURL() yr[HuwU
{ 3aERfIJyE
return sSiteURL; C|g]Y 7
} Jj'dg6QY'
jr3FDd]
Kq&JvY^
public void setSSiteURL(String value) ?5Q_G1H&
{ Br}0dha3E
sSiteURL = value; u8N"i),
} Xd@_:ds
"LkI'>3}
0`~#H1TK
public String getSFilePath() 0~=>:^H'`q
{ )D8V;g(7F
return sFilePath; <wj}y0(
} QQW]j;'~
oeF0t'%
~Blsj9a2
public void setSFilePath(String value) }:xj%?ki
{ x2$Y"b?vz
sFilePath = value; MgrJ ;?L
} Bnu5\P
5169E*
;Sw%t(@
public String getSFileName() >>R,P Ow-
{ 9 =zZ,dg
return sFileName; 0s o27k
} aF5=k:k
vI5'npM
Tp&7CNl|
public void setSFileName(String value) tXW7G@
{ !v?WyGbUg
sFileName = value; |0s)aV|K
} XFJz\'{
+xojnv
n"|1A..^
public int getNSplitter() vfpK|=[7o
{ y8/+kn +
return nSplitter; g>;u} +lO
} Nny#}k Bt
i_ z4;%#?
2e*"<>aeq
public void setNSplitter(int nCount) oQ/ Dg+Xp
{ 7CV}QV}G
nSplitter = nCount; S0jYk(
} 0;n}{26a
} p{W'[A{J .
`HV~.C
1azj%WY
/* Gcp!"y=i
**Utility.java :7DXLI|L#?
*/ CoTe$C7
package NetFox; |\6Ff/O
DQyy">]Mh
NsUP0B}.
public class Utility { Uk<2XGj
fiZq C?(
y*7<tj.`b0
public Utility() qJ%AbdOI8
{ ^7,`6g
jQ&82X%m
Msl8o c
} tEjT$`6hp
E.%_i8s
//线程睡眠 6o=Q;Mezl
public static void sleep(int nSecond) _n=,H
{ -E,p[Sp
try{ rls\3R(jt
Thread.sleep(nSecond); kCvf-;b
} %Qy9X+N:
catch(Exception e) MGfIA?u
{ _h0hl]rf
e.printStackTrace (); 5rUDRFO6
} F,/yK-9
} %(i(Cf8@
1 TA\6a}
//日志 1`v$R0`!
public static void log(String sMsg) pL pBP+i
{ iZn<j'u
System.err.println(sMsg); *e%(J$t
} Gf\u%S!%
hjx=?
~%d*#Yxq
public static void log(int sMsg) EB2 5N~7
{ v/z~ j
System.err.println(sMsg); CA5q(ID_
} X3l? YA
} ^<w3i?KPW
{1m.d;(1
XO,gEn&6V
/* tA{?-5
**TestMethod.java 5KRI}f
*/ H`EsFKw\%
package NetFox; hYY-Eq4TC
U8GvUysB!
!7y:|k,ac
public class TestMethod { k\A[p\
\z[L=
At)\$GJ
public TestMethod() m(p0)X),_i
{ ///xx/weblogic60b2_win.exe :!<U"AC
try{ Rb l4aB+
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); q^^&nz<A
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); J*m~fZ^
SiteFileFetch fileFetch = new SiteFileFetch(bean); 8c5%~}kG
fileFetch.start(); U~s-'-C/
} +?bjP6w_g
catch(Exception e){e.printStackTrace ();} #5=!ew
WN3]xw3
DxJY{e9
} 0p[-M`D
4)+L(KyB2
.y^T3?}I
public static void main(String[] args) 9KDm<Q-mf
{ ;k5B@z/<S
new TestMethod(); %hV]vm
} {<L|Z=&k`
} '/ *;g#W=
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