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)); ck K9@RQ
} &xMQ
for(int i=0;i<nEndPos.length-1;i++) (ixlFGvEq
{ _Q6` Wp6m
nEndPos = nStartPos[i+1]; b<"LUM*;
} Jqgo\r%`
nEndPos[nEndPos.length-1] = nFileLength; 5R/k8UZ
} N"&qy3F
} jv'q:uA^
37nGFH`K2m
\K(QE ~y'W
//启动子线程 OysO55i
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; |g8Q.*"l[
for(int i=0;i<nStartPos.length;i++) A<<Bm M.%
{ p-,(P+Np
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 8$y5) ~Q
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), i $;y
nStartPos,nEndPos,i); S# sar}-I
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); Sx}61?
fileSplitterFetch.start(); 40R7@Vaf
} 71!'k>]h
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), xr).ZswQ
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); S7WT`2
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", ,G!mO,DX
nEndPos = " + nFileLength); u<K{=94!e
// fileSplitterFetch[nPos.length-1].start(); T~b6Zu6
Nr:%yvk%s
{'1e?
//等待子线程结束 GP;UuQz
//int count = 0; &1$|KbmV4
//是否结束while循环 a7wc>@9Q,
boolean breakWhile = false; UZb!tO2
d0 qc%.s
LP:F'Q:<
while(!bStop) YB3?Ftgw
{ _omz74
write_nPos(); JWo).
Utility.sleep(500); \2NT7^H#
breakWhile = true; N(=\S:
56T{JTo
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for(int i=0;i<nStartPos.length;i++) mv\S1[<T
{ 9 7Mi{Zz
if(!fileSplitterFetch.bDownOver) 1JWo~E'
{ 9 `z^'k&
breakWhile = false; &24$*Oe
break; j]bNOC2.L
} ;Br #e1~
} .l}oxWWoS
if(breakWhile) ~Op~~ m
break; |]'0z0>
Tmr%r'i3
>^ijj`{d
//count++; Yi+$g
//if(count>4) z`KP }-
// siteStop(); &n-)Alx
} Z]x)d|3;
uhO-0H
35PIfqm
System.err.println("文件下载结束！"); #AUV&pI[
} CwQRHi
catch(Exception e){e.printStackTrace ();} S^*ME*DDz
} U t'r^
]B>g~t5J
ERZWK
//获得文件长度 G*\U'w4w|*
public long getFileSize() '7(oCab"_
{ *nc9u"
int nFileLength = -1; !@wG22iC4d
try{ 8lfKlXR78
URL url = new URL(siteInfoBean.getSSiteURL()); 2(iv+<t
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 8xQjJ
httpConnection.setRequestProperty("User-Agent","NetFox"); K6M_b?XekA
a<d$P*I(cH
k$v8cE
int responseCode=httpConnection.getResponseCode(); 6;{E-y
if(responseCode>=400) 9 Z79
{ do&0m[x%
processErrorCode(responseCode); )R@M~d-o
return -2; //-2 represent access is error *Ph@XkhU
} UcxMA%Pw7$
>nOzz0,
O)?
String sHeader; hR(p{$-T
!(>yB;u
.Mu]uQUF
for(int i=1;;i++) F=l.2t*9
{ 32Jl|@8,g
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); S1G3xY$0
//Utility.log(in.readLine()); mj_V6`m4
sHeader=httpConnection.getHeaderFieldKey(i); 6V^KOG
if(sHeader!=null) c!HmZ]/
{ mH)th7
if(sHeader.equals("Content-Length")) !y syb
{ {H[3[
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); WuUT>omH
break; sad[(|
} qS}pv
} )3A%Un#B
else 6Z7J<0
break; Z&j?@k,k
} |VE*_G
} CyEEE2cV
catch(IOException e){e.printStackTrace ();} TATH,Sz:x
catch(Exception e){e.printStackTrace ();} Bn?MlG;aA
AB")aX2%E
i8H!4l
Utility.log(nFileLength); =V*4&OU
R'1L%srTM+
5KvqZ1L
return nFileLength; 2z615?2_U
} pSh$#]mZ`
ti}G/*4
11jDAA(|
//保存下载信息（文件指针位置） \(a!U,]LM
private void write_nPos() tFKR~?Gc
{ Y:'#jY*V
try{ JBxizJBP
output = new DataOutputStream(new FileOutputStream(tmpFile)); 8j<+ ' R
output.writeInt(nStartPos.length); QQIU5
for(int i=0;i<nStartPos.length;i++) :dkBr@u96O
{ !|`vW{v
// output.writeLong(nPos); ;OD+6@Sr
output.writeLong(fileSplitterFetch.nStartPos); K}1eQS&$a
output.writeLong(fileSplitterFetch.nEndPos); Sw^-@w=!U5
} ]`GDZw`
output.close(); *&sXC@^@^
} Oxq} dX7S
catch(IOException e){e.printStackTrace ();} gg}^@h&?
catch(Exception e){e.printStackTrace ();} Z5%TpAu[
} }$T!qMst{
?~#{3b
`UH 1B/
//读取保存的下载信息（文件指针位置） aq<QKnU
private void read_nPos() P|{Et=R`1
{ [tY+P7j9)
try{ GYM6 `
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); [5O`
int nCount = input.readInt(); k>;a5'S
nStartPos = new long[nCount]; I7/X6^/}
nEndPos = new long[nCount]; /'g"Ys?3
for(int i=0;i<nStartPos.length;i++) UZ}>@0
{ UOtrq=y
nStartPos = input.readLong(); {%Ujp9i
nEndPos = input.readLong(); )}i;OLw-
} Q1(6U6L
input.close(); jYi{[**
} iJD_qhd7
catch(IOException e){e.printStackTrace ();} }j /r
catch(Exception e){e.printStackTrace ();} Q($aN-
} 2lm{:tS
*2tG07kI
Gaxa~?ek
private void processErrorCode(int nErrorCode) ZUxlk+o9d
{ !ii'hwFm$
System.err.println("Error Code : " + nErrorCode); O)i]K`jk
} </B5^}
06peo d
Z/>0P* F
//停止文件下载 (!9ybH;T
public void siteStop() 0;pOQF
{ ^S'tMT_
bStop = true; B{+ Ra
for(int i=0;i<nStartPos.length;i++) 70&]nb6f
fileSplitterFetch.splitterStop(); sBfPhBT|
en6oFPG
qmJ^@dxs
} <dA1n:3o
} 7/$s!pV
//负责部分文件的抓取 QC\][I>
**FileSplitterFetch.java zkrcsc\Z~0
*/ 2AZ)|dM'`
package NetFox; G,J~Ed
zrJ/Fs+s
u/2!v(
import java.io.*; s*0PJ\E2
import java.net.*; t%f6P
wWNHZv&
U'tfsf/V
public class FileSplitterFetch extends Thread { 0 w#[?.
Sn lKPd
&R "Q
String sURL; //File URL "x)xjL
long nStartPos; //File Snippet Start Position F]SA1ry
long nEndPos; //File Snippet End Position CL-mt5Kx#7
int nThreadID; //Thread's ID {,aI0bw;
boolean bDownOver = false; //Downing is over /\_wDi+#
boolean bStop = false; //Stop identical *NDM{WB|)
FileAccessI fileAccessI = null; //File Access interface *4tJ|m6"Y6
CNiUHUD
i@C$O.m(
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException D/&^Y'|T
{ < <vE.
this.sURL = sURL; lV0\UySH
this.nStartPos = nStart; "x*5g*k
this.nEndPos = nEnd; 5z>kz/uxW
nThreadID = id; k'K&GF1B
fileAccessI = new FileAccessI(sName,nStartPos);//定位 LJ|2=lI+jb
} AShnCL8uR
iJrF$Xw
F9Ag687w
public void run() 9w=GB?/
{ R""P01IZH
while(nStartPos < nEndPos && !bStop) oVLgHB\zL
{ ]$>O--
i:ZL0nH-
v3i]z9`
try{ BF_R8H,<%
URL url = new URL(sURL); rK%A=Q
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); '$3]U5KOwK
httpConnection.setRequestProperty("User-Agent","NetFox"); exqFwmhh
String sProperty = "bytes="+nStartPos+"-"; {5=Iu\e
httpConnection.setRequestProperty("RANGE",sProperty); YYz,sR'%|}
Utility.log(sProperty); 'xUyGj:
V2I"m
4Em mh=A
InputStream input = httpConnection.getInputStream(); E,[@jxP
//logResponseHead(httpConnection); na&?Cw
mOb*VH
5UQz6DK
byte[] b = new byte[1024]; [`~E)B1Y
int nRead; >h0iq
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) V #0F2GV<,
{ pb(YA/
nStartPos += fileAccessI.write(b,0,nRead); 3U<\s=1?X
//if(nThreadID == 1) zw`T^N#
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); c7[<X<yk
} <#s=78 g.3
)Qe4J0.
Nd.+Rs
Utility.log("Thread " + nThreadID + " is over!"); D~~&e<v'1
bDownOver = true; GnlP#;
//nPos = fileAccessI.write (b,0,nRead); kgX"LQh;[G
} zoV4Gl
catch(Exception e){e.printStackTrace ();} P,x'1`k~
} TX96 ^EoH
} @hlT7C)xK
UN <s1
=rA"|=
//打印回应的头信息 G6C#M-S
public void logResponseHead(HttpURLConnection con) E|t. 3
{ 5U&b")3IT!
for(int i=1;;i++) oh k.;
{ !1tHg Z2\
String header=con.getHeaderFieldKey(i); }7>r,
if(header!=null) :1q)l
//responseHeaders.put(header,httpConnection.getHeaderField(header)); s4@dEK8W
Utility.log(header+" : "+con.getHeaderField(header)); [X'XxYbZ
else qn VxP&
break; 7cGc`7
} d%:B,bck
} 2NHkK_B1P
M^c`j#NQ
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public void splitterStop() g]IRv(gDh
{ la7VeFT
bStop = true; '~HCYE:5
} 7~@9=e8G
#V[j Q Vl
d{cd+An
} 9E/{HNkf
B? $9M9
*C81DQ
/* 9 )1 8
**FileAccess.java =IQ+9Fl2
*//文件访问(定位，写) q6h'=By
package NetFox; ~c&ygL3
import java.io.*; 3;@/`Z_\lt
'OIOl
%#xdD2oN
public class FileAccessI implements Serializable{ {sn RS)-
Z)?i&y?
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 &Kuo|=f
RandomAccessFile oSavedFile; kdVc;v/5
long nPos; Zl5cHejM
F?UI8
C&\MDOjx
public FileAccessI() throws IOException d"K~+<V}
{ Zd~'%(q
this("",0); .+|HJ(
} :6k8\{^9"D
RRW/.y
u@j]U|FpY
public FileAccessI(String sName,long nPos) throws IOException )HHG3cvU
{ fqoI(/RWP
oSavedFile = new RandomAccessFile(sName,"rw"); S VCTiG8t
this.nPos = nPos; lSGtbSyDI
oSavedFile.seek(nPos); toDv~v
} 3uSj5+@q6
OF[y$<jM
)Gf"#TM[
public synchronized int write(byte[] b,int nStart,int nLen) Y>Oh]?
{ 0(!j]w"r3
int n = -1; K`7(*!HEb
try{ 4+rr3 $AY
oSavedFile.write(b,nStart,nLen); bXVH7Fy
n = nLen; F];"d0O#5
} z_Em%X
catch(IOException e) LA!2!60R
{ !i>&z?
e.printStackTrace (); (x;Uy
} `/W6,]
v|IPus|>
_Xs(3V@'}
return n; Q"o* \I
} Z>0a?=1[
|;~kHc$W
<SK%W=
} 5)tDgm
>3{#S:
q1rBSlzN
/* ]q#w97BxiJ
**SiteInfoBean.java ~ IPel
*/ iLQFce7d|&
package NetFox; L#t^:%
0:NCIsIm<
5k%GjT
public class SiteInfoBean { U/hf?T;
~.FeLWP
"H{Etb/
private String sSiteURL; //Site's URL Y[_{tS#u
private String sFilePath; //Saved File's Path D<V[:~-o
private String sFileName; //Saved File's Name Y^Of
private int nSplitter; //Count of Splited Downloading File ~3f`=r3/.
<1t.f}}uX
T0:%,o
public SiteInfoBean() I&2)@Zw
{//nSplitter的缺省值为5 }XOTK^YA
//default value of nSplitter is 5 C)x>/Qr~
this("","","",5); 47S1mxur
} EC`!&Yp+
r;>2L'
xIOYwVC
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) *d~).z)
{ ((& y:{?G
sSiteURL= sURL; caG5S#8-"
sFilePath = sPath; +c7e[hz
sFileName = sName; Ly\ `
this.nSplitter = nSpiltter; 8i epG
@fI1|v=eF
T^z
} B^7B-RBi0
I_?+;<n
)6~s;y!
public String getSSiteURL() [h5~1N
{ fGZZ['E
return sSiteURL; %-lilo
} c0I;8z`b
%S`ygc}|
hg2a,EU\Z
public void setSSiteURL(String value) ILN Yh3
{ sJI" m'r=Z
sSiteURL = value; aXv[~
} ec8iZ8h8
M0jC:*D`"
=d+~l
public String getSFilePath() )9pRT dT
{ oouhP1py,
return sFilePath; +69[06F
} `G@(Z:]f,t
QPD[uJ(I
`6No6.\J
public void setSFilePath(String value) 8QJ^@|7
{ "c9T4=]&t
sFilePath = value; K2Z]MpLD
} #F|q->2`o
zl]Ic' _i
(WCczXm)
public String getSFileName() -`f 1l8LD2
{ %%-?~rjI
return sFileName; qsA`\%]H
} u5'jIqlU
@K=:f
8|cQW-L
public void setSFileName(String value) [-5l=j r
{ (93$ L zZ
sFileName = value; OMY^'g%w
} 'DhH:PR
\kR:GZ`{UV
w/1Os!p
public int getNSplitter() B[$L)y'-;
{ uo TTHj7cq
return nSplitter; y/.I<5+Bu
} M#u~]?hS
0Tv0:c>8;(
ZZ? KD\S5
public void setNSplitter(int nCount) r|ID]}w
{ }J^+66{
nSplitter = nCount; LykB2]T
} r\j*?m ]
} w/oXFs&FK
O0Pb"ou_h.
2ophh/]
/* {W' 9k
**Utility.java P\rA>ZY
*/ `Eg~;E:
package NetFox; .T\jEH8E
,hVDGif
v =]!Po&Q-
public class Utility { 6k=*O|r
"9v4'"
]aZ3_<b
public Utility() %wQE lkB
{ GbwqrH+
PAy/"R9DT-
Dk^T_7{
} WJ&a9]&C
gucgNpX
//线程睡眠 %7v!aJ40
public static void sleep(int nSecond) s?yl4\]Muf
{ mHB0eB'l
try{ 7L4~yazmK
Thread.sleep(nSecond); F&_b[xso7
} ]r(&hqdR
catch(Exception e) WbwS!F<au
{ V|hr9
e.printStackTrace (); -Q MO*PY
} GlOSCJZ
} bjr()NM1
4(%LG)a4S
//日志 ~7$jW[i
public static void log(String sMsg) 4>NmJrh
{ x:E:~h[.^
System.err.println(sMsg); \LYNrL~?J
} Koi-b
2]V&]s8Wi=
DyCnL@
public static void log(int sMsg) >9+h2B
{ (hi{i
System.err.println(sMsg); 2DXV~>
} Q35D7wo'}
} IIY3/
|@Ze{\
2hf7F";Af
/* O gtrp)x9
**TestMethod.java j2`%sBo
*/ .L8g(F(=:
package NetFox; L#`Vr$
r!&}4lHYi
QIC? `hk1
public class TestMethod { VT2f\d[Q
mIW/x/I
Xk9 8%gv
public TestMethod() 'pHxO,vo
{ ///xx/weblogic60b2_win.exe y4N2gBTKu
try{ il[waUfmD
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); `6\u!#
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); q^eLbivVE
SiteFileFetch fileFetch = new SiteFileFetch(bean); nC5]IYL|
fileFetch.start(); VLcwBdo
} ,DD}o
catch(Exception e){e.printStackTrace ();} ho%G
4XgzNwm
f/vsf&^O
} .c]@xoC
I\<)9`O
$6~t|[7:%Y
public static void main(String[] args) P{2j31u`
{ hiw>Q7W
new TestMethod(); ;$g?W"
} 7_~_$I~g*
} x-s\0l
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