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)); ~1wdAq`'a
} >FMT#x t
for(int i=0;i<nEndPos.length-1;i++) TF}4X;3Dsy
{ \ /X!tlwxh
nEndPos = nStartPos[i+1]; WHD/s
} NId~|&\
nEndPos[nEndPos.length-1] = nFileLength; mGyIr kE
} oE|{|27X
} {dSU \':
iR}i42Cu
7+Jma!o
//启动子线程 2M(PH]D
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; BoiIr[ (
for(int i=0;i<nStartPos.length;i++) kvO`]>#;$?
{ %N_S/V0`
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), Ll E_{||h
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), J/P@m_Yx
nStartPos,nEndPos,i); +EB,7<5<
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 0.+Z;j
fileSplitterFetch.start(); g9r5t';
} W0?Y%Da(4m
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 51(`wo>LS
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); B6!<@*BI
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", IkXKt8`YVA
nEndPos = " + nFileLength); |EEz>ci
// fileSplitterFetch[nPos.length-1].start(); S bqM=I+
p~zTRnm
a518N*]j
//等待子线程结束 o!_; H}pq
//int count = 0; Qj~W-^/ -
//是否结束while循环 (9[C0eS
boolean breakWhile = false; G>{:D'#
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s"Pk-Dv
while(!bStop) i\R\bv[9
{ Ai_|)
write_nPos(); q!h*3mNm
Utility.sleep(500); )b2E/G@X&
breakWhile = true; yW=hnV{
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for(int i=0;i<nStartPos.length;i++) )1yUV*6
{ ujHzG}2z
if(!fileSplitterFetch.bDownOver) ZtK%b+MBP
{ p2f WL
breakWhile = false; =`.5b:e
break; $=g.-F%*=
} rxK[CDM,
} d~f0]O
if(breakWhile) 9qO:K79|
break; rpP+20v
YHv,Z|.w
MVU'GHv
//count++; iO=uXN1g
//if(count>4) qxCL
// siteStop(); 2dJ)4
} `r0 qn'*
n7!Lwq2
lJQl$Wx^
System.err.println("文件下载结束！"); 7)It1i-
} \U =>
catch(Exception e){e.printStackTrace ();} 28qWC~/9
} 8P y_Y>
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`YU:kj<6
//获得文件长度 &#\7w85$
public long getFileSize() 5}^08Xl
{ L5|;VH
int nFileLength = -1; SE-, 1p
try{ XK9*,WA9r
URL url = new URL(siteInfoBean.getSSiteURL()); ~9jP++&
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); &IPK5o,
httpConnection.setRequestProperty("User-Agent","NetFox"); 73Zs/
Nm :lC%>X
GN"LU>9|
int responseCode=httpConnection.getResponseCode(); GQAg ex)D
if(responseCode>=400) ^|12~d_.T
{ Y%cA2V\#m
processErrorCode(responseCode); 7Z:l;%]K
return -2; //-2 represent access is error P*=3$-`
} l8Iy03H
7(iRz
hQLx"R$
String sHeader; E0%Y%PQ**{
F"? *@L
?BZ`mrH^
for(int i=1;;i++) X1QZEl
{ k#G7`dJl
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); (dnc7KrM
//Utility.log(in.readLine()); K]Cs2IpI
sHeader=httpConnection.getHeaderFieldKey(i); iK0J{'
if(sHeader!=null) >bP7}T
{ a_MnQ@
if(sHeader.equals("Content-Length")) QF6JZQh<
{ F&j|Y>m
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); p" W0$t.
break; z`{zqP:
} &y wY?ox
} e~[z]GLO%
else d33Nx)No
break; 7027@M?A?
} `5jB|r/
} dllf~:b
catch(IOException e){e.printStackTrace ();} fszeJS}Dw
catch(Exception e){e.printStackTrace ();} &=O1Qg=K
AS^$1i:
tce8*:rNH
Utility.log(nFileLength); mK/P4]9g
&jd<rs5}
}ZGpd9D
return nFileLength; &8L\FAY0%9
} TTak[e&j3
3Ya6yz
k$- q;VI
//保存下载信息（文件指针位置） Eu~wbU"%
private void write_nPos() JU+'UK630
{ KftM4SFbK
try{ Pu*UZcXY
output = new DataOutputStream(new FileOutputStream(tmpFile)); |VF"Cjw?
output.writeInt(nStartPos.length); X,CFY
for(int i=0;i<nStartPos.length;i++) LMj'?SuH
{ nECf2>Yp v
// output.writeLong(nPos); N2Hb19/k
output.writeLong(fileSplitterFetch.nStartPos); \`# 0,pLr
output.writeLong(fileSplitterFetch.nEndPos); HBGA lZ
} %+J*oFwQu
output.close(); S*@0%|Q4r
} U MIZ:*j
catch(IOException e){e.printStackTrace ();} T<GD!j(
catch(Exception e){e.printStackTrace ();} 7OHw/-j\
} V2skr_1
[)c|oh%
84cH|j`w
//读取保存的下载信息（文件指针位置） 4u7>NQUDu
private void read_nPos() RL8wSK
{ ?saVk7Z[|5
try{ Ka2tr]+s
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); SXF_)1QO\W
int nCount = input.readInt(); aBLb i
nStartPos = new long[nCount]; L#bQ`t
nEndPos = new long[nCount]; ay[*b_f
for(int i=0;i<nStartPos.length;i++) GQWTQIl]
{ d'D\#+%>=
nStartPos = input.readLong(); ?"u-@E[m
nEndPos = input.readLong(); Ux]@prAq
} 1yc@q8
input.close(); E.9k%%X]
} |/Z)?
catch(IOException e){e.printStackTrace ();} p8J"%Jq}
catch(Exception e){e.printStackTrace ();} )S?}huX
} H.K`#W&
w+P^c|
yBKlp08J
private void processErrorCode(int nErrorCode) `vBa.)u
{ i|'t!3I^m
System.err.println("Error Code : " + nErrorCode); pSUp"wch
} ZK*aVYnu
y$NG..S
_.LWc^Sg
//停止文件下载 x*)O<K
public void siteStop() @U5>w\
{ ?Qk#;~\yB
bStop = true; )CQ}LbXZy
for(int i=0;i<nStartPos.length;i++) 3Re\ T
fileSplitterFetch.splitterStop(); Ev#aMK
. %7A7a
4f,x@:Jw
} PCjY,O
} n3,wwymQ
//负责部分文件的抓取 gu&oCT
**FileSplitterFetch.java ij5YV3
*/ KR0 x[#.*
package NetFox; %Ski5q
i*j+<R@
`h6W@ROb
import java.io.*; b*fflJ
import java.net.*; " z{w^k
_r'M^=yx[
3J<,2
public class FileSplitterFetch extends Thread { {Wo7=aR
1fZ:^|\
1YL5 ![T
String sURL; //File URL bux-t3g7+
long nStartPos; //File Snippet Start Position L;`t%1
long nEndPos; //File Snippet End Position k6S<46}h|
int nThreadID; //Thread's ID O?Tg`]EX
boolean bDownOver = false; //Downing is over ?Y* PVx9Y
boolean bStop = false; //Stop identical YZ@-0_Z
FileAccessI fileAccessI = null; //File Access interface \f#ao<vQm
Ymom 0g+f
YvX I
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException [*t EHW
{ v(~m!8!TI
this.sURL = sURL; qC1@p?8$
this.nStartPos = nStart; -^DB?j+
this.nEndPos = nEnd; UtN>6$u
nThreadID = id; jfamuu7
fileAccessI = new FileAccessI(sName,nStartPos);//定位 B?Skw{&
} (%}C
Z ngJ9js
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public void run() wP*Z/}Uum+
{ ,jmG!qJb
while(nStartPos < nEndPos && !bStop) 3FN? CN] O
{ 3LREue7Gr
RSC-+c6 1
_(foJRr
try{ -f=hL7NW
URL url = new URL(sURL); /jD'o>
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); KG$2u:n
httpConnection.setRequestProperty("User-Agent","NetFox"); ig{5]wZ(
String sProperty = "bytes="+nStartPos+"-"; -s"lW 7N^
httpConnection.setRequestProperty("RANGE",sProperty); iXFaQ
Utility.log(sProperty); A$cbH.
h;->i]
-yeT$P&|
InputStream input = httpConnection.getInputStream(); ZI7<E
//logResponseHead(httpConnection); )RFeF!("
Sqs`E[G*
x#D=?/~/Kv
byte[] b = new byte[1024]; 3 6 ;hg#
int nRead; {W]jVh p
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) AK HH{_
{ g:U ul4
nStartPos += fileAccessI.write(b,0,nRead); cht#~d
//if(nThreadID == 1) CggEAi~
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); O;2 u1p'iP
} b3+PC$z2h
S6]':
1oPT8)[U
Utility.log("Thread " + nThreadID + " is over!"); >q`X%&l_
bDownOver = true; "dOzQz*E
//nPos = fileAccessI.write (b,0,nRead); eAMT72_
} ?F/3]lsggT
catch(Exception e){e.printStackTrace ();} *rLs!/[Z_
} )T?ryp3ev
} KXJHb{?
k&b>-QP6
}8HLyK,4
//打印回应的头信息 i7FEjjGtG
public void logResponseHead(HttpURLConnection con) :z\STXq
{ )c/] 8KU
for(int i=1;;i++) @_{"ho
{ $4&Ql
String header=con.getHeaderFieldKey(i); `c(@WK4
if(header!=null) rzu^br9X
//responseHeaders.put(header,httpConnection.getHeaderField(header)); ;QYK {3R?
Utility.log(header+" : "+con.getHeaderField(header)); U,'n}]=4A3
else :&m(WZ\
break; #=rR[:M
} 7F.,Xvw&@
} art{PV4-
m| Z)h{&
\ (,2^T'$J
public void splitterStop() H< j+-u4b
{ L6m'u6:1{
bStop = true; Nu'rn*Y_
} Q*he%@w
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wrbDbp1L
} =u(fP" |{
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^|Y!NHYH$Z
/* -LyIu#
**FileAccess.java ze-iDd_y
*//文件访问(定位，写) h>wU';5#f
package NetFox; bm;4NA?Gg
import java.io.*; ]9' \<uR
rhrlEf@
gP3[=a"\
public class FileAccessI implements Serializable{ )Ii=8etdv
zy|hf<V
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 P1t5-q
RandomAccessFile oSavedFile; '&9b*u";x(
long nPos; ;>~iCFk]?
mS0W@#|K
Wh,kJis<
public FileAccessI() throws IOException @9-qqU@
{ STI8[e7{
this("",0); >2a~hW|,
} Sz =z TPnO
<*[(t;i
%X3T<3<
public FileAccessI(String sName,long nPos) throws IOException D<MtLwH
{ \21!NPXH2
oSavedFile = new RandomAccessFile(sName,"rw"); bu]bfnYi9
this.nPos = nPos; GB#7w82
oSavedFile.seek(nPos); d^7<l_u~ !
} !Ej<J&e
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(f)QEho7
public synchronized int write(byte[] b,int nStart,int nLen) FEkx&9]
{ s[hD9$VB>
int n = -1; t?\osPL
try{ {S?.bT%&
oSavedFile.write(b,nStart,nLen); W+QI D/
n = nLen; DD1S]m
} kW"N~Xw)
catch(IOException e) m`/OO;/;
{ s SDBl~g
e.printStackTrace (); 0:XmReO+k
} )lZb=t
%EuSP0
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return n; <*L8kNykK
} E:2Or~
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PH6uP]
} 2'D2>^os
j9%=^ZoQj
{'/8{dS
/* >1YJETysO
**SiteInfoBean.java JH 8^ZP:d'
*/ /wQDcz
package NetFox; {J[0UZ6
k{; 2*6b0
V[~/sc )
public class SiteInfoBean { Lr`yl$6
(uSfr]89'
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private String sSiteURL; //Site's URL #(OL!B
private String sFilePath; //Saved File's Path bS*9eX=K
private String sFileName; //Saved File's Name >6c{CYuT
private int nSplitter; //Count of Splited Downloading File #<{sP0v*
T!8,R{V]4
*cf#:5Nl
public SiteInfoBean() SO|$X
{//nSplitter的缺省值为5 p?5zwdX+`
//default value of nSplitter is 5 "_lSw3
this("","","",5); ?Pa5skqR
} I'JFt>]
`U(FdT
kxh $R>
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) KcHW>IBxdv
{ `On%1%k8
sSiteURL= sURL; :V&#Oo
sFilePath = sPath; -LUKYGBK
sFileName = sName; /)j:Y:5
this.nSplitter = nSpiltter; {a(TT)d
$. Ih-
zhS\|tI
} n;[d{bU
06ZyR@.@v
uT_bA0jK
public String getSSiteURL() lwSA!W
{ k/>k&^?
return sSiteURL; Z<`QDBN"4
} 3qP! (*
nBR4j?':i
yN9/'c~
public void setSSiteURL(String value) />H9T[3=
{ #}o*1
sSiteURL = value; }5`Kn}rY
} L^dF )y?
Y-v6xUc{F
(m13 ong
public String getSFilePath() `j9 ;9^
{ A2..gs/
return sFilePath; arm26YA-,
} X-=49)
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public void setSFilePath(String value) #V@[<S2
{ 4PR!OB
sFilePath = value; Lc=t,=OhGe
} m;'ebkq
w=,bF$:fIW
S/V%<<[>p]
public String getSFileName() 9J*.'Y
{ K9]L>Wj
return sFileName; ",Mr+;;:[
} Dc2H<=];
\<TWy&2&
+xp)la.
public void setSFileName(String value) m9 1Gc?c
{ @kd`9Yw
sFileName = value; h:xvnyaI
} <v%Q|r
0-6rIdDTM
:pq+SifP
public int getNSplitter() -e(e;e
{ `p#tx.o
return nSplitter; 8MU+i%hd
} I;FHjnn(
EV/DJ$C }
)\Am:?RH;
public void setNSplitter(int nCount) B 1jeIk,
{ -%,=%FBi~4
nSplitter = nCount; yw\Q>~$n[=
} {OIB/
} =bgWUu\F
kntYj}F(
W[/Txc0$
/* ]Q$Sei5
**Utility.java }p5_JXBV
*/ Kl_(4kQE_
package NetFox; 3$G &~A{
g8kS}7/
>cJix 1
public class Utility { 0fu*}v"
8 kvF~d ;
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public Utility() \(_(pcl
{ /*P) C'_M
$O3.ex V
@CMEmgk~
} "zj[v1K9-A
T[Lz4;TRk5
//线程睡眠 [n4nnmM
public static void sleep(int nSecond) Wz%H?m:g#
{ [4w*<({*
try{ agt/;>q\~
Thread.sleep(nSecond); Hsn'"
} C~Hhi-Xl)
catch(Exception e) zX lcu_rc
{ .exBU1Yk@
e.printStackTrace (); uP G\1
} ml@;ngmp.
} `J]e.K
u8.F_'`z
//日志 _AzI\8m
public static void log(String sMsg) y4U|~\]
{ > a;iX.K
System.err.println(sMsg); zzK<>@c
} 90#* el
4O<sE@X
R:4@a ':H
public static void log(int sMsg) ]"}BqS0
{ hjyM xg;Q?
System.err.println(sMsg); By waD?
} _B>'07D0
} }yVx"e)
.' }jd#
O uNPDq%
/* ?r0rY?
**TestMethod.java `WIZY33V
*/ , #=TputM
package NetFox; }`kiULC'=
A'BqNsy
{n|ah{_p|
public class TestMethod { "AU.Eh"-1
nNq<x^@83
D=Q.Q
public TestMethod() >$7x]f
{ ///xx/weblogic60b2_win.exe hr;^.a^
try{ ;plBo%EBV
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); )X?oBNsj
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); Mgr?D
SiteFileFetch fileFetch = new SiteFileFetch(bean); "\i H/
fileFetch.start(); U0t|i'Hx
} fcxg6W'
catch(Exception e){e.printStackTrace ();} P0yDL:X[
v^ "qr?3V
BBM[Fy37!}
} ,`JYFh M
sC.b'1P
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public static void main(String[] args) rRg,{:;A
{ D'<L6w`
new TestMethod(); R\|,GZ!`+
} hw,nA2w\
} Vm|KL3}NRv
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