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)); C(*@-Npf[
} S!!\!w>N
for(int i=0;i<nEndPos.length-1;i++) 2/4x]i H*
{ .'mC3E+$
nEndPos = nStartPos[i+1]; F20-!b
} `&[:!U2]F
nEndPos[nEndPos.length-1] = nFileLength; YJvT p~
} -&D6w9w
} f#Cdx"
j~f 7WJ
`"mK\M
//启动子线程 %c/"A8{eb
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; Afhx`J1KO
for(int i=0;i<nStartPos.length;i++) :XZom+>2n
{ {#M{~
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), >37}JUG
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), x Bw.M{
nStartPos,nEndPos,i); 'yRv~BA
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); mf_'| WDs
fileSplitterFetch.start(); m9w ;a
} I%C:d#p
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), Bo\v-97
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); ?F!J@Xn5
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", 5N+(Gv[`"
nEndPos = " + nFileLength); F8;4Oj
// fileSplitterFetch[nPos.length-1].start(); s^R2jueR
E^W*'D
>P"/nS"nn
//等待子线程结束 \0T*msYQ
//int count = 0; Xt*%"7yTp
//是否结束while循环 f/i,Zw
boolean breakWhile = false; +9rbQ?'
JP@m%Yj
X&oy.Roo
while(!bStop) -vfu0XI~
{ f_2^PF>?
write_nPos(); 5nqdY*
Utility.sleep(500); 9}$dwl(
breakWhile = true; D c.WvUM
3Il/3\
afq +;Sh
for(int i=0;i<nStartPos.length;i++) n(Op<
{ )^#Zg8L
if(!fileSplitterFetch.bDownOver) {&qsh9ob
{ L\CM);y
breakWhile = false; G*p.JsZP
break; O|zmDp8a+
} ?ML<o>OKg
} /M `y LI
if(breakWhile) ,5uDEXpt{
break; 8vo7~6yy
|RXC;zt9s
v$/i5kcWx
//count++; B_jI!i{N%o
//if(count>4) }C`0" 1
// siteStop(); 8&hn$~ate
} Dohe(\C@
W%Q>< 'c
>Nl~"J|]q
System.err.println("文件下载结束！"); >M85xjXP
} 7gmMqz"z(>
catch(Exception e){e.printStackTrace ();} *`'%tp"'+
} ,8?*U]}
IVODR
Cs=i9.-A
//获得文件长度 =C1Qo#QQ%
public long getFileSize() ([o:_5/8I
{ ]=<@G.[=
int nFileLength = -1; J uKaRR~
try{ ,?~,"IQyi[
URL url = new URL(siteInfoBean.getSSiteURL()); pR>QIZq<gT
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); %~XJwy-
httpConnection.setRequestProperty("User-Agent","NetFox"); z4:09!o_
pvxqeC9`
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int responseCode=httpConnection.getResponseCode(); g c=|<(
if(responseCode>=400) -3U} (cZ*
{ 7B"aFnK;[J
processErrorCode(responseCode); )WJI=jl
return -2; //-2 represent access is error $:Zxb
} lfd{O7L0b
Ap18qp
[/j-d
String sHeader; GQxJ (f
8so}^2hTlT
_Fy:3,(
for(int i=1;;i++) PP|xIAc
{ $& gidz/w
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); w`f~Ht{wYR
//Utility.log(in.readLine()); !&%bl
sHeader=httpConnection.getHeaderFieldKey(i); '-TFrNO;h
if(sHeader!=null) o|E(_Y4d
{ Kx!|4ya,
if(sHeader.equals("Content-Length")) scwlW b<N
{ s_kd@?=`x
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); vB4qJ{f
break; 5X|aa>/
} |<icx8hbr
} vtjG&0GSK
else ,kuOaaV7K
break; sOenR6J<$
} c3-bn #
} [/]3:|
catch(IOException e){e.printStackTrace ();} $7g(-W
catch(Exception e){e.printStackTrace ();} #R|4(HlL
h8;"B
Mt0|`=64
Utility.log(nFileLength); Ut@)<N
zaPR>:r0
THZ3%o=X
return nFileLength; l]cQ7g5
} cn{l %6K
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"$9ZkADO
//保存下载信息（文件指针位置） .<hv&t
private void write_nPos() l>q.BG
{ :g_ +{4
try{ d^>se'ya
output = new DataOutputStream(new FileOutputStream(tmpFile)); roQIP%h!
output.writeInt(nStartPos.length); a)b@en;v
for(int i=0;i<nStartPos.length;i++) <{j9|mt
{ L1K_|X
// output.writeLong(nPos); > xw+2<
output.writeLong(fileSplitterFetch.nStartPos); Xu0*sQK
output.writeLong(fileSplitterFetch.nEndPos); #y%Ao\~kG
} 9a unv
output.close(); ktb.fhO
} ^jA}*YP
catch(IOException e){e.printStackTrace ();} #{sb>^BF
catch(Exception e){e.printStackTrace ();} I`1=VC]^8
} O[5ti=W
@^@-A\7[KO
p%'((!a2
//读取保存的下载信息（文件指针位置） #kEdf0
private void read_nPos() PX'%)5:q;i
{ X_2I4Jz]6
try{ ['<rfK
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); 7#QH4$@1P
int nCount = input.readInt(); nK$m:=
nStartPos = new long[nCount]; e{/\znBS%
nEndPos = new long[nCount]; Joj8'
for(int i=0;i<nStartPos.length;i++) Zx0c6d!B
{ 4mg&H0 !
nStartPos = input.readLong(); xa:P(x3[
nEndPos = input.readLong(); >[U$n.
} t&]IgF
input.close(); %yVZ|d*Q
} = %m/
catch(IOException e){e.printStackTrace ();} T@.CwV
catch(Exception e){e.printStackTrace ();} u@Lu.t!],
} uOx$@1v,
!j@ 8:j0WY
q\<vCKI-^
private void processErrorCode(int nErrorCode) oY: "nE
{ ;MD{p1w
System.err.println("Error Code : " + nErrorCode); g(Nf.hko
} ^4:= b
usip>y
Ws(>} qjy
//停止文件下载 R_}(p2
public void siteStop() @ ri.r1
{ czzV2P/t}
bStop = true; ] $*cmk(Y
for(int i=0;i<nStartPos.length;i++) &0`L;1R
fileSplitterFetch.splitterStop(); q ^?{6}sy
R<)uvW_@
+Xk!)Ge5E*
} K||85l?<
} _ev^5`>p/
//负责部分文件的抓取 I/l]Yv!
**FileSplitterFetch.java Z8W<RiR
*/ )_uK(UNZ5
package NetFox; ~jaGf
y;H 3g#
\<%a`IA!*
import java.io.*; [+GG Wo
import java.net.*; &!=3Fbn
g;pymz
wpvaTHo
public class FileSplitterFetch extends Thread { |bh:x{h
-eya$C
4^5s\f B
String sURL; //File URL {+MMqJCa
long nStartPos; //File Snippet Start Position \BDNF<_
long nEndPos; //File Snippet End Position ]_h"2|
int nThreadID; //Thread's ID h4CB1K
boolean bDownOver = false; //Downing is over FP$]D~DMo
boolean bStop = false; //Stop identical ]!QeJ'BLM
FileAccessI fileAccessI = null; //File Access interface O-k(5Zb
Q1rwTg\
.B@;ch,
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException 0M"E6z)9
{ IlVi1`]w
this.sURL = sURL; 6S(3tvUr
this.nStartPos = nStart; %K%z<R8
this.nEndPos = nEnd; c-,/qn/
nThreadID = id; LQe<mZ<
fileAccessI = new FileAccessI(sName,nStartPos);//定位 ]=/f`
} _Z%C{~,7)x
8LL);"$
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public void run() +W}f0@#)<
{ l\eq/yg_
while(nStartPos < nEndPos && !bStop) lUrchLoDt
{ rRMC<.=
vDemY"wz
S=o/n4@}
try{ E5rNC/Ul$$
URL url = new URL(sURL); O/-xkzR*
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); Y#G '[N>
httpConnection.setRequestProperty("User-Agent","NetFox"); Vj_ $%0
String sProperty = "bytes="+nStartPos+"-"; Uhf -}Jdw
httpConnection.setRequestProperty("RANGE",sProperty); c{[d@jtO
Utility.log(sProperty); pq@ad\8
gaJS6*P#
h)w<{/p(
InputStream input = httpConnection.getInputStream(); _Nd\Cm
//logResponseHead(httpConnection); 79Iz,_
Eb*DP_
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byte[] b = new byte[1024]; -V\33cA
int nRead; FKaY w
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) c;Li~FLR
{ 5d)G30
nStartPos += fileAccessI.write(b,0,nRead); (Az^st/_
//if(nThreadID == 1) X(8]9
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 2/GH5b(
} 4CDmq[AVS[
Qr/?tMALc
0Y\u,\GrxW
Utility.log("Thread " + nThreadID + " is over!"); .w0?
bDownOver = true; DQ,QyV
//nPos = fileAccessI.write (b,0,nRead); Y$N|p{Z
} 9:P)@UF
catch(Exception e){e.printStackTrace ();} 6ik6JL$AI
} Axr'zc
} !nu#r$K(
' _N >
'?QZ7A
//打印回应的头信息 1vobfZ-w9
public void logResponseHead(HttpURLConnection con) Y}0-&
{ /%.K`BMN
for(int i=1;;i++) Y.-i;Mmu
{ c;j]/R$i
String header=con.getHeaderFieldKey(i); [ML4<Eb+x
if(header!=null) ?)9 6YX'
//responseHeaders.put(header,httpConnection.getHeaderField(header)); U_w)*)F
Utility.log(header+" : "+con.getHeaderField(header)); ':HV9]k
else mCg5-E~;
break; '0[l'Dt'
} 7n#0eska,
} tJ 6:$dh
fd(>[RP?
*?c~7ru
public void splitterStop() zj8;ENhEI
{ e Q0bx&
bStop = true; ?L_#AdK
} *FO']D
~Su>^T(?-
$BG9<:p
} pt<84CP
g|W~0A@D
r8@:Ko= a
/* {D7!'Rq,
**FileAccess.java pnf3YuB
*//文件访问(定位，写) }=wSfr9g
package NetFox; 0evG
import java.io.*; m(9E{;
i^ 1P6B
ak<?Eu9rV
public class FileAccessI implements Serializable{ @mW0EJ8bb
JBuorc
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 1,4kw~tA
RandomAccessFile oSavedFile; ,"&vhgYU
long nPos; ]Qj65]
~fr1O`8
[j&>dE
public FileAccessI() throws IOException %uQ^mK
{ #B54p@.}
this("",0); F> ..eK
} WWD\EDnS
yfYAA*S!z
anv_I=
public FileAccessI(String sName,long nPos) throws IOException G3KiU($V
{ W/fM0=!
oSavedFile = new RandomAccessFile(sName,"rw"); GAQVeL1
this.nPos = nPos; ~bgFU
oSavedFile.seek(nPos); R9{6$djq\:
} E-l>z%
9erTb?@S
jMgNi@
public synchronized int write(byte[] b,int nStart,int nLen) Jzh_`jW0l
{ 89~)nV)
int n = -1; ?9/%K45
try{ 0^zu T
oSavedFile.write(b,nStart,nLen); VYvHpsI
n = nLen; *S*;rLH9c
} %]d^B|
catch(IOException e) 8DyE
{ 0YW<>Y`6
e.printStackTrace (); .{~ygHQ`f
} }KJ/WyYW
AuSL?kZ4|Y
z;1yZ4[G
return n; p-MQI }
} <^OGJ}G
n&k1'KL&
|7%M:7Q
} jR*1%.Ng
v;irk<5
lZ'NLbK
/* ,f4Hl%T;
**SiteInfoBean.java e>X&[\T
*/ y1FS?hSD0
package NetFox; e~jp< 4
yG{'hx6H
9^>nZ6
public class SiteInfoBean { `nn;E%n
BIS5u4
q>f1V3
private String sSiteURL; //Site's URL Q;Xb-\\
private String sFilePath; //Saved File's Path q=Q5s?sQc
private String sFileName; //Saved File's Name "m(HQ5e)*
private int nSplitter; //Count of Splited Downloading File =[3I#s?V
Lw1~$rZg
3/P2&m
public SiteInfoBean() 0vf2wBK'T
{//nSplitter的缺省值为5 pv;}Sv$ ]-
//default value of nSplitter is 5 l. !5/\
this("","","",5); xLX:>64'o>
} 6E85mfFS
' !ZFK}
T^%$
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) px".pYr0
{ $D<LND=o=
sSiteURL= sURL; _L<IxOZh+
sFilePath = sPath; FNtcI7
sFileName = sName; 44]/rP_m
this.nSplitter = nSpiltter; 9^x'x@6
&qF
[$ vAjP
} ESL(Mf'
V1,O7m+F2
[C.Pzo
public String getSSiteURL() ;WWUxrWif
{ VYMs`d[
return sSiteURL; vrLI`3n]
} 1s"6
&FW|O(]
*C}vy`X
public void setSSiteURL(String value) 1-Sc@WXd
{ q!t_qX7u
sSiteURL = value; XSkx<"U*
} t,)`Zu$
,=.&
R*VJe+5w
public String getSFilePath() m?`U;R[
{ ?L|m:A`
return sFilePath; +Gg6h=u
} 2<y!3OeN
]KBzuz%
(ylpH`
public void setSFilePath(String value) )u7y.o
{ i*_T\_=
sFilePath = value; tn>$5}^;
} 4U(W~O
UMuRB>ey
p;,Cvw{.;%
public String getSFileName() Zx@/5!_n.
{ MDM/~Qpj_
return sFileName; :U$<h
} Lp`q[Z*
hB]4Tn5H
b%z4u0
public void setSFileName(String value) )#%k/4(Y
{ 82O#Fe q
sFileName = value; 0B7cpw>_J
} .BuXg<`
pdUrVmW"'
FZ)_WaqGf
public int getNSplitter() <DxUqCE
{ 2^'|[*$k1@
return nSplitter; .v?Ir)
} \#?n'qyj
s,!+wHv_8
?ey!wcv~
public void setNSplitter(int nCount) *G"L]Nq#
{ +] s"*'V$
nSplitter = nCount; hN=YC\l
} QVA)&k'T,
} eo.y,Uh
38ChS.(
j-e/nZR@
/* 2ys'q!
**Utility.java By%mJ%$~
*/ WqlX'tA
package NetFox; ky0Fm W
Lf`LFPKb
35|F?Jx.r
public class Utility { !$ItBn/_
}d?"i@[
yhhW4rz
public Utility() =B-a]?lM
{ yqi=9NB
o&g-0!"
~"6/OJA
} \D}K{P
)FVW/{NF@q
//线程睡眠 g?'pb*PR
public static void sleep(int nSecond) ^LO=&Cq
{ ;j|T#-.
try{ O{:_-eI&d
Thread.sleep(nSecond); O4H %x
} a"ZBSg(
catch(Exception e) -L<''2t
{ NZ`Mq
e.printStackTrace (); XMzL\Edo
} Z\Qa6f!
} ky*-THS
sz4)xJgF(
//日志 yyCx;
public static void log(String sMsg) f-!t31?XK
{ 7UM!<@9\
System.err.println(sMsg); WtlPgT;wE
} ;[9WB<t
vl+vzAd
K.'II9-{
public static void log(int sMsg) OT/*|Pn9
{ 8JvF4'zx
System.err.println(sMsg); H~y 7o_tg
} s"G;rcS}#
} l;_zXN
^wDZg`
$w!;~s
/* AT.WXP0$A
**TestMethod.java $!F_K
*/ c@iP^;D
package NetFox; ^,F8 ha
AWSe!\b
E{_$C!.
public class TestMethod { &aD]_+b
svki=GD_(.
a:nMW'!
public TestMethod() 3N%%69JN)
{ ///xx/weblogic60b2_win.exe -OY[x|0
try{ 0NKo)HT
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); V-rzn171Q)
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); 'fB/6[bd
SiteFileFetch fileFetch = new SiteFileFetch(bean); R?bF b|5t
fileFetch.start(); &Xw{%Rg
} 5T]GyftFV
catch(Exception e){e.printStackTrace ();} aDr46TB`J
P){F2&!P
eTi r-7
} {p#[.E8
Okd?=*sBx
n$>E'oG2t
public static void main(String[] args) v"x{oD$R
{ ;533;(d*o
new TestMethod(); j(JUOief
} +Ja9p
} 38(Cj~u=3
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