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)); '~n=<Y
} 8ps1Q2|
for(int i=0;i<nEndPos.length-1;i++) _[{oK G^u
{ _64<[2
nEndPos = nStartPos[i+1]; <ql:n
} .s`7n *xz
nEndPos[nEndPos.length-1] = nFileLength; 5O]eD84B
} |3dIq=~1"Y
} K/|qn)
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GK[[e~#u
//启动子线程 nna boD
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; 6(-c$d`C.0
for(int i=0;i<nStartPos.length;i++) ,'a[1RN
{ a{+;&j[!
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), [9,34/i
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), my*E7[
nStartPos,nEndPos,i); ,%$Cfu
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); fk'DJf[M
fileSplitterFetch.start(); 9YVr9BM'K
} 6UAw9 'X8
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), jM;?);Dd
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); CQI\/oaO
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", ucX!6)Op
nEndPos = " + nFileLength); ~NZ}@J{00_
// fileSplitterFetch[nPos.length-1].start(); 7~2V5@{<
<~P([5
3Ss)i7
//等待子线程结束 ,Lr}P
//int count = 0; TF-a1z
//是否结束while循环 mExJ--}
boolean breakWhile = false; #bCzWg
Bt(U,nFB
(/gMtIw
while(!bStop) )g[7XB/w
{ (F'?c1
write_nPos(); 6;p"xC-
Utility.sleep(500); *#c^.4$'
breakWhile = true; cW?~]E'<
x4[ Fn3JL
(k24j*1e$
for(int i=0;i<nStartPos.length;i++) mL]5Tnc
{ r)Fd3)e
if(!fileSplitterFetch.bDownOver) jGFDj"Y
{ jOU1F1
breakWhile = false; 3 , nr*R!
break; ydf;g5OZ
} 2/RW(U
} !Tu4V\^~A
if(breakWhile) 'OvyQ/T
break; ^/"2s}+
3TF'[(K=
KK41I8Mw
//count++; L]QBh\
//if(count>4) aT}?-CUxx
// siteStop(); P/ 7aj:h~P
} L^{wxOf&6E
{z*`* O@
8Lh[>|~=
System.err.println("文件下载结束！"); &d&nsQ
} N7}yU~j^
catch(Exception e){e.printStackTrace ();} 'jjJ[16"d
} dY'>'1>P 9
}(v <f*7=n
eN-lz_..7
//获得文件长度 S\W&{+3
public long getFileSize() c*Q6k<SKR
{ 3?-2~s3gp
int nFileLength = -1; 8npjQ;%4>
try{ 5gH'CzU?
URL url = new URL(siteInfoBean.getSSiteURL()); QIu!o,B
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); %tZ[wwt
httpConnection.setRequestProperty("User-Agent","NetFox"); ;7bY>zc(w
/*hS0xN*
7,,#f&jP
int responseCode=httpConnection.getResponseCode(); ~_W>ND
if(responseCode>=400) Jec<1|
{ 'Z`fZ5q
processErrorCode(responseCode); _VI3b$
return -2; //-2 represent access is error ~=9]M.$
} )ioIn`g^-
fhbILg
D0@d}N
String sHeader; ]R6Z(^XT,E
vH/Y]Am
9<6Hs3|.!
for(int i=1;;i++) A:YWXcg
{ <PTi>C8;r
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); g].v
//Utility.log(in.readLine()); Mp)|5<%
sHeader=httpConnection.getHeaderFieldKey(i); uW^W/S%'
if(sHeader!=null) | sZu1K
{ ,7*-%05[\
if(sHeader.equals("Content-Length")) )kK" 1\m
{ Ps9YP B-
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); Wkc^?0p
break; VO+3@d:
} ["XS|"DM
} C^!ej"
else E K#ib
break; ^9xsbv B0
} 8`;3`lZ
} -[-Ry6G
catch(IOException e){e.printStackTrace ();} &$hT27A>k
catch(Exception e){e.printStackTrace ();} C 8qVYrw
H\ONv=}7I
atWB*kqI
Utility.log(nFileLength); 6Rc%P)6
C;.+ kE
S[L2vM)
return nFileLength; OCYC Dn
} B)L;ja
Dd$CN&Ca
kU$M 8J.
//保存下载信息（文件指针位置） j aq/]I7
private void write_nPos() ljRR{HOl
{ NZ?|#53
try{ .47tj`L
output = new DataOutputStream(new FileOutputStream(tmpFile)); 4Q FX
output.writeInt(nStartPos.length); .Wq"
for(int i=0;i<nStartPos.length;i++) ~L=Idt!9
{ jj*e.t:F
// output.writeLong(nPos); M}W};~V2ng
output.writeLong(fileSplitterFetch.nStartPos); tx{tIw^2;
output.writeLong(fileSplitterFetch.nEndPos); i=8){GX4
} `-[+(+["
output.close(); LTt|"D
} 1$adX
catch(IOException e){e.printStackTrace ();} sKuPV
catch(Exception e){e.printStackTrace ();} 7{:g|dX
} 5N4[hQrVJ
B^sHFc""V
Zfn390_
//读取保存的下载信息（文件指针位置） (VA:`pstP
private void read_nPos() SK_i 3?
{ b1`(f"&l
try{ 4<QSot
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); lg!{?xM
int nCount = input.readInt(); Pw_[{LL
nStartPos = new long[nCount]; #3o]Qo[Sc
nEndPos = new long[nCount]; 13:0%IO
for(int i=0;i<nStartPos.length;i++) 1F_ 1bAh$
{ B)`^/^7
nStartPos = input.readLong(); &.t|&8-
nEndPos = input.readLong(); ;Z(~;D
} =\l7k<
input.close(); |xQq+e}l<
} Uv"GG: K_
catch(IOException e){e.printStackTrace ();} niIjatT
catch(Exception e){e.printStackTrace ();} 1GL@t?S
} $S0eERga
ooPH [p
34P5[j!h
private void processErrorCode(int nErrorCode) !^*I?9P
{ <r{ )*]#l
System.err.println("Error Code : " + nErrorCode); k(v8zDq*
} ET7(n0*P}]
4?a!6
2!^[x~t
//停止文件下载 -O=a"G=
public void siteStop() (iZE}qf7g
{ X@ Gm:6
bStop = true; );.q:"
for(int i=0;i<nStartPos.length;i++) ;qF#!Kb5
fileSplitterFetch.splitterStop(); (~>L \]!
j!H\hj/]
`y!6(xI
} t"@:a Y"
} _,M:"3;Z
//负责部分文件的抓取 (mJqI)m8
**FileSplitterFetch.java H.ZmLB
*/ Sh_=dzM
package NetFox; ?"no~(EB
@Pc]qu
l&d 6G0
import java.io.*; g(0 |p6R
import java.net.*; $LF
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K"sfN~@rT[
public class FileSplitterFetch extends Thread { KR6*)?c`
NgnHo\)
*L9s7RR
String sURL; //File URL T$'GFA
long nStartPos; //File Snippet Start Position ?wR;"
long nEndPos; //File Snippet End Position wxg`[c$:
int nThreadID; //Thread's ID RJ_ratKN*g
boolean bDownOver = false; //Downing is over <(Wa8PY2(
boolean bStop = false; //Stop identical <M1XG7_I
FileAccessI fileAccessI = null; //File Access interface g&*pk5V>
X]Emz"
dsP1Zq
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException !(hP{k ^g
{ cmIAWFj-)e
this.sURL = sURL; Hize m!
this.nStartPos = nStart; 7FVu[Qu
this.nEndPos = nEnd; ^#R-_I
nThreadID = id; nNIV(
fileAccessI = new FileAccessI(sName,nStartPos);//定位 _ID2yJ
} Oifu ?f<r
X"W%(x`w
PomX@N}1
public void run() nzTzc5 w
{ 9_rNJLj8y
while(nStartPos < nEndPos && !bStop) 8E/]k\
{ SrN;S kS
]rDf3_!m(
h@72eav3+
try{ $;_'5`xs
URL url = new URL(sURL); ,$habq=;
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); m%$z&<!
httpConnection.setRequestProperty("User-Agent","NetFox"); ^b`}g
String sProperty = "bytes="+nStartPos+"-"; 1WPDMLuN
httpConnection.setRequestProperty("RANGE",sProperty); qB_MDA
Utility.log(sProperty); <,l&),
| %af}# FQ
8kih81tx"U
InputStream input = httpConnection.getInputStream(); qphN
//logResponseHead(httpConnection); I~qS6#%r
Fz16m7.
8=7u,t
byte[] b = new byte[1024]; QJo)
int nRead; !GMb~
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) n]x4twZ
{ _y)#N<
nStartPos += fileAccessI.write(b,0,nRead); \qAMs^1-
//if(nThreadID == 1) y'Xg"
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); +7o3TA]-
} e+=Ojo#
kRskeMr:Rd
qqSk*oH~
Utility.log("Thread " + nThreadID + " is over!"); "gdmRE{x
bDownOver = true; ASAz<H$
//nPos = fileAccessI.write (b,0,nRead); d'Z|+lq:
} H!&]Di1Eh
catch(Exception e){e.printStackTrace ();} vI]| W
} BpCzmU
} PDX^MYoN
O!sZMGF$p
]?^m;~MQZ
//打印回应的头信息 (]>c8;o#b
public void logResponseHead(HttpURLConnection con) 6Pl$DSu
{ 'M+iVF6
for(int i=1;;i++) -) $$4<L
{ =4yME
String header=con.getHeaderFieldKey(i); lMp)T**
if(header!=null) -<}_K,Ky`
//responseHeaders.put(header,httpConnection.getHeaderField(header)); qSMSTmnQ
Utility.log(header+" : "+con.getHeaderField(header)); El0|.dW
else Og%qv Bj 6
break; #:z.Br`
} DI9x]CR
} HPpKti7g
Aa.bE,W
V_!hrKkL
public void splitterStop() }Fyf?TZ$T
{ hkv&Od,
bStop = true; ,a< !d
} 8:-[wl/@
J}KATpHs
w*Sl
} 1I KDp]SN
A;w,m{9<
'HkV_d[li
/* cy?u *
**FileAccess.java Revc :m1o
*//文件访问(定位，写) M'HmVg4'
package NetFox; hp,bfcM
import java.io.*; _i:yI-jA
O~-#>a
>mT2g
public class FileAccessI implements Serializable{ 2@1A,
&K)c*'l
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 {Rjj
RandomAccessFile oSavedFile; s{KwO+UW
long nPos; 6I72;e^!
4'?kyTO~
Fc7mAV=
public FileAccessI() throws IOException @xB"9s
{ kfg9l?R$I<
this("",0); D>~z{H%\
} .'p_j(uv
+l2{EiQw
1>4'YMdZi
public FileAccessI(String sName,long nPos) throws IOException S!2M?}LU
{ *xM4nUu<~
oSavedFile = new RandomAccessFile(sName,"rw"); yu<sd}@
this.nPos = nPos; %ztCcgu*
oSavedFile.seek(nPos); Dx/?0F7V
} 4iRcmsP
A/W0O;*q
}X)mZyM[
public synchronized int write(byte[] b,int nStart,int nLen) ]k]P (w
{ lycY1lK
int n = -1; 6jiVz%`=Z
try{ zm9>"(H
oSavedFile.write(b,nStart,nLen); |9jeOV}/
n = nLen; :|M0n%-X
} YT}m 8Y
catch(IOException e) 'F?T4
{ t@>Uc`%
e.printStackTrace (); |OUr=b
} W'-B)li
@.a[2,o_
pqBd#
return n; d11~mU\
} GG5wiN*2S
#<S+E7uTs
4EJ
} votv rZ=
hoD (G X
4H]Go~<
/* Im+<oZ
**SiteInfoBean.java TPt<(-}W
*/ /^G1wz2
package NetFox; 6OF&Q`*4
D1;H,
D?)91P/R
public class SiteInfoBean { ,Za!
,H2[["1DH
[:
private String sSiteURL; //Site's URL i!LEA/"V
private String sFilePath; //Saved File's Path Z[RE|l{
private String sFileName; //Saved File's Name =[FNZ:3
private int nSplitter; //Count of Splited Downloading File 200/
ly7\H3
"H" 4(3
public SiteInfoBean() ;x$,x-
{//nSplitter的缺省值为5 Jv %,v?
//default value of nSplitter is 5 \ty{KAc&
this("","","",5); b<P9@h~:
} 0WaC.C+2i
B?`Gs^Y{z
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public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) |`1lCyV\tE
{ D kl4^}
sSiteURL= sURL; JQj?+PI
sFilePath = sPath; 4%LGPh
sFileName = sName; |77.Lqqy,
this.nSplitter = nSpiltter; fr#Y<=Jo
"G].hKgbk*
)pJ} $[6
} y>_lxLhmO#
J70#pF
(, /`*GC
public String getSSiteURL() CH[U.LJQ-O
{ =J&vr
return sSiteURL; 'X d_8.
} s {p-cV
V##=-KZ
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public void setSSiteURL(String value) xeF0^p7Z
{ c Owa^;
sSiteURL = value; RSC^R}a5
} <^c?M[j
y[:\kI
9=O`?$y
public String getSFilePath() l=ehoyER
{ gHpA@jdC*
return sFilePath; HQJ_:x Y
} 5ltEnvN
it.Lh'N;T
k&wCa<Rs~R
public void setSFilePath(String value) j*+[=X/
{ |T\`wcP`q
sFilePath = value; OC34@YUj[
} &TJMopVn
NF8'O
meey5}
public String getSFileName() 6<X.]"u+E~
{ XHs>Q>`
return sFileName; a9]F.Jm
} (8T36pt~
oS6dcJHf
`G7LM55
public void setSFileName(String value) A#;6~f
{ fy]z<SPhVJ
sFileName = value; tljZE)
} 8T<LNC
zG-pqE6
(K9pr>le
public int getNSplitter() .TZ0FxW
{ [A~n=m5H
return nSplitter; } DQ<YF+
} WV5z~[
RN:VsopL
{zzc/!|
public void setNSplitter(int nCount) N{+6V`\
{ UU\wP(f
nSplitter = nCount; %!DdjC&5*
} TwPpZ@
} zplAH!s5''
P:D@5
W5i{W'
/* RJ}%pA4I
**Utility.java @M( hyS&on
*/ 7x>\/l(
package NetFox; v7-z<'?s~
_*iy *:(o
PmjN!/
public class Utility { +"}#4
vciO={M
FYBW3y+AF&
public Utility() 8O^<#lh
{ hW<TP'Zm*
uuaoBf
(#e,tu
} Mo'6<"x
t[e`wj+qz
//线程睡眠 cG)U01/"
public static void sleep(int nSecond) DXF>#2E^+
{ Mi^/`1
try{ i<\WRzVT
Thread.sleep(nSecond); \wR;N/tg
} kR0/jEz C
catch(Exception e) 6uS;H]nd<
{ \d)HwO
e.printStackTrace (); 5ho!}K
} TI5<' U)
} !8Y$}
-3GlpC22
//日志 Cfr2~w
public static void log(String sMsg) +b sc3
{ }'`iJb\
System.err.println(sMsg); h"}c_lY9
} Zdfruzl&`
@f!r"P]
mXwDB)O{)
public static void log(int sMsg) 2}uSrA7n]
{ -|DBO0q
System.err.println(sMsg); 7lUnqX.
} <Z j>}
} 0/5{v6_rG
S*l=FRFI
1v~1?+a\2
/* 9,jFQb(),
**TestMethod.java Y3.^a5o
*/ \o}=ob
package NetFox; $tqr+1P
M@]@1Q.p
Ba}<X;B}
public class TestMethod { >&[q`i{
GL-Pir
Mi<l;ZP
public TestMethod() Dqg01_O9O
{ ///xx/weblogic60b2_win.exe =))VxuoN
try{ Yln[ZmK9g
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); "Z]z9(
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); LEd@""h
SiteFileFetch fileFetch = new SiteFileFetch(bean); 3~EPX`#[W
fileFetch.start(); ja&S^B^@
} KY+BXGW*
catch(Exception e){e.printStackTrace ();} m%%\k \
kYZj^tR
O`f[9^fN
} 6KE?@3;Om
|t6:4']
J-ErG!
public static void main(String[] args) .#{m1mr
{ 06NW2A%wv
new TestMethod(); l.uW>AoLh
} ;m~%57.;\
} 1StaQUB
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