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)); qv:DpK
} k%sxA
for(int i=0;i<nEndPos.length-1;i++) 2zv:j7
{ c;a<nTLn
nEndPos = nStartPos[i+1]; ^,f^YL;
} d mTZEO
nEndPos[nEndPos.length-1] = nFileLength; F]<2nb7
} %SCt_9u
} r1=j$G
/&czaAR-
QWt3KW8)
//启动子线程 -V"W
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; T>hm\!
for(int i=0;i<nStartPos.length;i++) +.rOqkxJ
{ W|sU[dxZ
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), {z;K0
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), NP4u/C<
nStartPos,nEndPos,i); Gv#bd05X
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); oxI?7dy5
fileSplitterFetch.start(); xwwL
} VH+3o?nrT
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), X(#8EY}X
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); 3U!=R-
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", 1IT(5Mleb
nEndPos = " + nFileLength); xBf->o S?
// fileSplitterFetch[nPos.length-1].start(); <{YzmN\Z
n`jG[{3t&
@FF{lK?[
//等待子线程结束 0$=U\[og
//int count = 0; 'w<^4/L Q
//是否结束while循环 FGm!|iI
boolean breakWhile = false; 0~[M[T\
6iHY{WcDj
B*tQ0`
while(!bStop) xwHE,ykE
{ XJwgh y?(
write_nPos(); t56PzT'M
Utility.sleep(500); 7A$mZPKh
breakWhile = true; 2#/sIu-L
,C_MB1u
nYvkeT
for(int i=0;i<nStartPos.length;i++) &5B/>ag1!
{ @LS%uqs
if(!fileSplitterFetch.bDownOver) j+gh*\:q
{ 7Xh @%[
breakWhile = false; e5;YY
break; x'6i9]+r
} $GhL-sqm
} & \"cV0
if(breakWhile) KilN`?EJ
break; jzWgyI1b
yWT1CID
$DnR[V}rR!
//count++; nT}i&t!q8@
//if(count>4) _c:th{*
// siteStop(); P"@^BQ4
} #8BI`.t)j
hew"p(`
GyFA1%(o
System.err.println("文件下载结束！"); ,u-9e4
} 1C*mR%Q
catch(Exception e){e.printStackTrace ();} 4V mUTMY
} 2$o\`^dy
VrhHcvnZ
!#e+!h@
//获得文件长度 4((p?jbC
public long getFileSize() (b"q(:5oX
{ 0Xn,q]@Z
int nFileLength = -1; sP=^5K`g
try{ N{M25ucAHl
URL url = new URL(siteInfoBean.getSSiteURL()); h^14/L=|
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); ^\yz`b(A0
httpConnection.setRequestProperty("User-Agent","NetFox"); 0|=y#`;,Z
jj 'epbA
*Z2Ko5&Y2
int responseCode=httpConnection.getResponseCode(); E7B?G3|z3
if(responseCode>=400) =fB"T+
{ N+pCC
processErrorCode(responseCode); yi(IIW
return -2; //-2 represent access is error XCXX(8To0=
} @s,kx.S
A.$P1zwC
Q0ba;KPm
String sHeader; 5rQu^6&
V<ilv<
2nL*^hhh
for(int i=1;;i++) W}%[i+
{ :j/sTO=
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); |=:hUp Jp
//Utility.log(in.readLine()); u6MU @?
sHeader=httpConnection.getHeaderFieldKey(i); )?6%d
if(sHeader!=null) f9d{{u
{ rD !GEU
if(sHeader.equals("Content-Length")) Qj|tD+<
{ O]!o|w(
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); t2m7Yh5B
break; -q?,
} .5 {<bY
} 1vJj?Uqc
else }` <DKO/
break; g!cW`B'
} Ya!PV&"Z
} ?_T[]I'
catch(IOException e){e.printStackTrace ();} *|;`Gp
catch(Exception e){e.printStackTrace ();} RfT)dS+rAh
J L1]auO*
8{6`?qst@
Utility.log(nFileLength); @_ UI;*V
"/3YV%to-#
N]\)Ok
return nFileLength; nD!t*P
} ]xbMMax
j}fSz)`i
e]{=#
//保存下载信息（文件指针位置） (iJ /
private void write_nPos() ^7=h%{>=
{ >Dz8+y
try{ =hI;5KF
output = new DataOutputStream(new FileOutputStream(tmpFile)); TS=U%)Ik
output.writeInt(nStartPos.length); ;sx4w!Y,
for(int i=0;i<nStartPos.length;i++) s'Qmrs a
{ :H:+XIgoR
// output.writeLong(nPos); -e0?1.A$
output.writeLong(fileSplitterFetch.nStartPos); WKwYSbs(
output.writeLong(fileSplitterFetch.nEndPos); 3|EAOoWnK
} NR%_&%qQA
output.close(); S/YHT)0x[
} 2NB$(4/
catch(IOException e){e.printStackTrace ();} 8CH9&N5W5t
catch(Exception e){e.printStackTrace ();} 6#a82_
} C+dz0u3s
g*w}m>O
JLg/fB3%
//读取保存的下载信息（文件指针位置） OAgZeK$
private void read_nPos() )XoMOz
{ k3]qpWKj
try{ Q"3gvIyc
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); HLL=.:P
int nCount = input.readInt(); pkTVQdtRG
nStartPos = new long[nCount]; b%d,X-3
nEndPos = new long[nCount]; iDltN]zS
for(int i=0;i<nStartPos.length;i++) ^E~1%Md.
{ W[>qiYf^b
nStartPos = input.readLong(); yDj'')LOQg
nEndPos = input.readLong(); Kp;a(D
} SQMtR2
input.close(); %CUwD
} =T)y(] ;M$
catch(IOException e){e.printStackTrace ();} @![1W@J
catch(Exception e){e.printStackTrace ();} TpdYU*z_Br
} 9`KFJx6D
S9'Xsh
u7 <VD
private void processErrorCode(int nErrorCode) r-Y7wM`TZ
{ +k/=L9#e
System.err.println("Error Code : " + nErrorCode); wbg?IvY[
} K1&t>2=%
_3#_6>=M
$)KNpdXh
//停止文件下载 SA%)xGRW
public void siteStop() rMw$T=Oi
{ QB;TQZ
bStop = true; yf4 i!~
for(int i=0;i<nStartPos.length;i++) ~3%aEj
fileSplitterFetch.splitterStop(); H;ujB \+
j8^zE,Z
. K_Jg$3
} 8I<j"6`+Q
} 9Sl5jn
//负责部分文件的抓取 xmfZ5nVL
**FileSplitterFetch.java I$XwM
*/ Tl+PRR6D*
package NetFox; `P$X`;SwE
Fzn!
0<^Qj.(9
import java.io.*; Vo|[Z)MO`
import java.net.*; ~ftR:F|9
]3Jb$Q@
C^:{y
public class FileSplitterFetch extends Thread { V6kDyl(
ID<[=es6
KTeR;6oZn"
String sURL; //File URL k`s_31<
long nStartPos; //File Snippet Start Position 0n={Mb
long nEndPos; //File Snippet End Position 90ov[|MkM
int nThreadID; //Thread's ID kv2 H3O
boolean bDownOver = false; //Downing is over 2Zg%4/u,Zp
boolean bStop = false; //Stop identical g[\8s~g,
FileAccessI fileAccessI = null; //File Access interface -"XHN=H
7|o}m}yVx
%zhSSB=BJ
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException 3T[zieX
{ czB),vooz
this.sURL = sURL; b'vIX< g
this.nStartPos = nStart; _ D"S
this.nEndPos = nEnd; Vl'rO_?t
nThreadID = id; /J(~NGT
fileAccessI = new FileAccessI(sName,nStartPos);//定位 :?>yi7w
} &'?Hh(
- rI4_Dl
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public void run() Z4m+GFY
{ =c%gV]>G
while(nStartPos < nEndPos && !bStop) #RKd>ig%
{ Ds{DVdqA$c
LCe6](Z
57_AJT hR
try{ 2tQ?=V(Di
URL url = new URL(sURL); _{GD\Ai_W
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 8v=t-GJW
httpConnection.setRequestProperty("User-Agent","NetFox"); +WguWLO"
String sProperty = "bytes="+nStartPos+"-"; QT|\TplJt
httpConnection.setRequestProperty("RANGE",sProperty); Z!4B=?(
Utility.log(sProperty); J~h9i=4<bF
O5:[]vIn
A+z}z@K
InputStream input = httpConnection.getInputStream(); 1DN
//logResponseHead(httpConnection); jLw|F-v-l<
-U;=]o1
c_aj-`BKp
byte[] b = new byte[1024]; kZR(0, W
int nRead; /03?(n= 3
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) NL'(/|)
{ {s=c!08=
nStartPos += fileAccessI.write(b,0,nRead); ^S(QvoaQ
//if(nThreadID == 1) A-h[vP!v|
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); .}E@7^X
} :W+%jn
}}oIZP\qM
s%A?B8,
Utility.log("Thread " + nThreadID + " is over!"); aPX'CG4m
bDownOver = true; 14(ct
//nPos = fileAccessI.write (b,0,nRead); hE'>8{
} x Vw1
catch(Exception e){e.printStackTrace ();} ]@CXUa,>a
} |;"(C# B
} ?uW} XAi
O>9-iqP>`d
v9Lf|FXo&
//打印回应的头信息 k4` %.;
public void logResponseHead(HttpURLConnection con) 4{0vdpo3F
{ /XdLdA!v
for(int i=1;;i++) MVEh<_
{ 5fLp?`T
String header=con.getHeaderFieldKey(i); n'1LNi
if(header!=null) c2]h.G83
//responseHeaders.put(header,httpConnection.getHeaderField(header)); S$a.8Xh
Utility.log(header+" : "+con.getHeaderField(header)); Fw^^sB
else b27t-p8
break; Rhw+~gd*F
} :*cd$s
} 'CRjd~L
[]?*}o5&>T
/74)c~.W
public void splitterStop() Gsz$H_
{ ]}.|b6\
bStop = true; ^Of\l:q*
} g``S SU
c4bvJy8
7Oi<_b
} t&IWKu#
>;}(?+|f
-<tTT
/* Vygh|UEo
**FileAccess.java Gc;-zq
*//文件访问(定位，写) /sqfw,h@
package NetFox; f*^bV_
import java.io.*; \)2'+R
ZbH_h]1$D
j_b/66JyN
public class FileAccessI implements Serializable{ Zj0h0Vt
l>("L9
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 -.-@|*5
RandomAccessFile oSavedFile; %~0]o@LW7
long nPos; 51ILR9 Bc_
(.b!kfC
9QeBz`lm)
public FileAccessI() throws IOException $-\%%n0>6
{ cVSns\QO
this("",0); ~N)(|N
} $-(lp0\*
_6L'}X$)N
7}(YCZny5
public FileAccessI(String sName,long nPos) throws IOException =r&i`L{]
{ X3y28 %R
oSavedFile = new RandomAccessFile(sName,"rw"); !"ydl2
this.nPos = nPos; @}'?o_/C
oSavedFile.seek(nPos); @k/|%%uP
} bvT$/(7
`u8(qGg7GF
r'@7aT&_
public synchronized int write(byte[] b,int nStart,int nLen) bKh}Y`
{ y-Lm^GW4
int n = -1; J?jxD/9Yb
try{ Iomx"y]9
oSavedFile.write(b,nStart,nLen); oMNBK/X_
n = nLen; m`4N1egCt
} GZmfE`
catch(IOException e) +hs:W'`%
{ +KIBbXF7
e.printStackTrace (); Xod/GYG
} Q{ {=
A^4#6],%v
s1X?]A
return n; ^xr &E
} C]3^:b+
5{-54mwo
&0+Ba[Z ^
} gGs"i]c
ifmX<'(9A
-)DxF<8B
/* 4OG1_6K
**SiteInfoBean.java i\* b<V
*/ %V(U]sbV
package NetFox; 0bu!(Tpg7
qR4-~p8
vI(CX]o
public class SiteInfoBean { q%XjJ -s:
@J6V,
&7eN EA
private String sSiteURL; //Site's URL 6?/f$,v
private String sFilePath; //Saved File's Path =$_kkVQ$
private String sFileName; //Saved File's Name )1<GSr9
private int nSplitter; //Count of Splited Downloading File oF s)UR
xzf/W+.>.
~e5E%bXxC
public SiteInfoBean() O1oh,~W
{//nSplitter的缺省值为5 /5Yl, P
//default value of nSplitter is 5 S4!B;,?AxN
this("","","",5); 'Xasd3*Py
} t;y@;?~
>Hd!o"I
hS^8/]E={
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) <JW%h :\t
{ 7&Ie3[Rm_3
sSiteURL= sURL; -r[O_[g w
sFilePath = sPath; :GM3n$
sFileName = sName; `/(9#E
this.nSplitter = nSpiltter; R l)g[s
Y*S(uqM
:S+Bu*OyH
} 0.B'Bvn=s2
m4R:KjN*
$-39O3
public String getSSiteURL() c7R6.T
{ !]&+g'aC3
return sSiteURL; ] B>.}
} ~hT(uxU/
TR:4$92:H
4u1au1c
public void setSSiteURL(String value) f;bfR&v
{ Mp@dts/|
sSiteURL = value; Yr>7c1FZi
} +,eF(VS!
9Wdx"g52_D
n9k-OGJ
public String getSFilePath() >{"E~U
{ Na+3aM%%
return sFilePath; 1:q`KkJx
} ZD4:'m`T/
zSBR_N51
6N/6WrQEeg
public void setSFilePath(String value) 7<LCX{Uw
{ "lB%"}
sFilePath = value; ]5e|W Q>*X
} 2xv[cpVi
VD+v\X_
(?[%u0%_
public String getSFileName() H4W!@"e
{ [u^~ND'
return sFileName; xQNGlVipZ@
} kXOc)
F1%^,;
eo&G@zwN
public void setSFileName(String value) m=60a@o]
{ 4UMOC_
sFileName = value; /'bX}H(dq
} , Q)
<ti,Wn.
6U1_Wk?
public int getNSplitter() jEL"Q?#
{ #`%V/#YK
return nSplitter; z -'e<v;w
} Q3[nS(#Z/=
B_"PFWwg
b{.Y?.U
public void setNSplitter(int nCount) l=<},_]{
{ 5 axt\
nSplitter = nCount; 5e^z]j1Yv
} v|nt(-JX
} }5}#QHF
Z OqD.=O(
;b 'L2
/* Qa"4^s
**Utility.java 5-:H
*/ yp<)v(8|'
package NetFox; Y0ACJ?|
=h/61Bl3
zT'(I6S:)
public class Utility { ;ao <{i?
zRB LkrC
S~^]ib0
public Utility() ESuP ZB
{ Cjj(v7[E
)O>M~
',I$`h
} gj82qy\:
nE4rB\
//线程睡眠 /pJr%}sc
public static void sleep(int nSecond) !)(To
{ G9CL}=lJ,
try{ Pxgal4{6
Thread.sleep(nSecond); Z.N9e
} h@Ix9!?+
catch(Exception e) WmE4TL^8?
{ n.1$p
e.printStackTrace (); 7/dp_I}cO
} X @X`,/{X
} 7Kti&T
(mx}6A
//日志 9-y<= )
public static void log(String sMsg) ^O**ZndB/
{ ^j<2s"S
System.err.println(sMsg); M+7jJ?n
} Cm-dos
cpx:4R,
*\^(-p~M
public static void log(int sMsg) )~#3A@
{ $"3cN&
System.err.println(sMsg); _w7yfZLv+
} UhSaqq
} Q1x=@lXR
cZAf?,>u
\_/dfmlIZ
/* _"82W^Wi
**TestMethod.java Nk?/vMaw
*/ ]F"@+_E
package NetFox; o1[[!~8e
HyIyrUrYW
`Nv7c{M^
public class TestMethod { KnUVR!H|
[2z >8SL
8aW<lu
public TestMethod() >&Vz/0
{ ///xx/weblogic60b2_win.exe #}[NleTVt
try{ 8B6-f:
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); l$C Y gm
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); #m3!U(Og`
SiteFileFetch fileFetch = new SiteFileFetch(bean); ~FnY'F<35
fileFetch.start(); `dIwBfg_
} @[]#[7
catch(Exception e){e.printStackTrace ();} 6e"Lod_ L
^[b DE0
M/YS%1
} (.kzJ\x
HaQox.v%
ccy q~
public static void main(String[] args) @E=77Jn[px
{ Jl ?_GX}ZY
new TestMethod(); ^(7Qz&q
} p-,Bq!aG$
} *Z3b6X'e
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