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)); hz|z&vyP
} 96E7hp !:
for(int i=0;i<nEndPos.length-1;i++) 88=FPEU
{ +FKP5L}
nEndPos = nStartPos[i+1]; _wJ#jJz2
} =28H^rK{
nEndPos[nEndPos.length-1] = nFileLength; A_*Lo6uII
} |b@A:8ss
} ]4Yb$e`
IV#My9}e
OZ0%;Y0
//启动子线程 +PXfr~ 4
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; Ty|c@X
for(int i=0;i<nStartPos.length;i++) W9m[>-Ew
{ E=~WQ13Q
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), dv}R]f'
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), ^F0jI5j).
nStartPos,nEndPos,i); Y'H/ $M N
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); Q pc^qP^-
fileSplitterFetch.start(); ~zC fan/
} kQ'xs%Fw
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), Q/`o6xv
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); 0bL=l0N$W
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", >#n-4NZ;p9
nEndPos = " + nFileLength); b/}0 &VXo
// fileSplitterFetch[nPos.length-1].start(); %!h+
>5:e1a?9
:+^llz
//等待子线程结束 'wq:F?viF
//int count = 0; 1L qJ@v0
//是否结束while循环 dY`J,s
boolean breakWhile = false; ]@T `qR
l8lR5<
/j\TmcnU^
while(!bStop) y'wW2U/1-
{ /[dAgxL
write_nPos(); |i}g7
Utility.sleep(500); <rmV$_
breakWhile = true; rGL{g&_
0DT2qM[,
MdjMTe s
for(int i=0;i<nStartPos.length;i++) leJd){
{ x)mC^
if(!fileSplitterFetch.bDownOver) :!FwF65
{ 6x8|v7cMH
breakWhile = false; \1_&?(pU
break; yvwcXNXR@
} )`7h,w J[1
} M<pgaB0
if(breakWhile) FEswNB(]*
break; Oip..f0
t4f\0`jN
..mz!:Zs0
//count++; tJ=zk3BN~
//if(count>4) SVz.d/3Y
// siteStop(); 7Wn]l!
} $ayD55W4
a8c]B/
d_B5@9e#
System.err.println("文件下载结束！"); t4uxon
} `d#_66TLr
catch(Exception e){e.printStackTrace ();} 1_]l|`Po
} ?&_\$L[
[}3Y1t{G
^[akB|#\9
//获得文件长度 ![jP)WgF
public long getFileSize() I]1fH
{ /Vc!N)
int nFileLength = -1; &t4(86Bmq
try{ +R$KEGu~0Y
URL url = new URL(siteInfoBean.getSSiteURL()); YdaJ&
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); ;Yj&7k1
httpConnection.setRequestProperty("User-Agent","NetFox"); OD|&qsbL
aH~"hB^e
_Z&R'`kg
int responseCode=httpConnection.getResponseCode(); +__Rk1CVh
if(responseCode>=400) $<PVzW,$o
{ dI|/Xm>
processErrorCode(responseCode); wS4wED&a
return -2; //-2 represent access is error x]T;W&s
} LJx g
\ 3N#%
Fsh-a7Qp
String sHeader; o}z}79Z
]W,g>91m
_i#Z'4?2E
for(int i=1;;i++) V>Cf 8>m
{ \Qn8"I83AV
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); i`;I"oY4
//Utility.log(in.readLine()); Z(P#]jI]
sHeader=httpConnection.getHeaderFieldKey(i); EzaOg|
if(sHeader!=null) RZjR d
{ N8TO"`wdbs
if(sHeader.equals("Content-Length")) @@QU"8q
{ IcZ'KV
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); zD'gGxM1
break; &~8}y+z
} _1~Sj*
} "7DPsPs
else frt?*|:
break; ]F~5l?4u#
} M<729M
} [*(MI 9WM
catch(IOException e){e.printStackTrace ();} +Muyp]_
catch(Exception e){e.printStackTrace ();} ?l/rg6mbI'
@tA.^k0`
= N#WwNC
Utility.log(nFileLength); ntT|G0E
t65!2G"<
a5iMCmL+
return nFileLength; `#V"@Go
} vR,'':
=%p"oj]:
_:z~P<%s
//保存下载信息（文件指针位置） DEBgb
private void write_nPos() tv0xfAV
{ 1\2 m'o
try{ d3\8BKp
output = new DataOutputStream(new FileOutputStream(tmpFile)); #%5>}$
output.writeInt(nStartPos.length); L%DL n
for(int i=0;i<nStartPos.length;i++) =P!Vi6[gF~
{ iw{n|&Y#`
// output.writeLong(nPos); VYwaU^
output.writeLong(fileSplitterFetch.nStartPos); 5^xt/vYa)
output.writeLong(fileSplitterFetch.nEndPos); P/_XDP./U
} 3B0%:Jj
output.close(); Fri5_rxLl
} \S9z.!7v$
catch(IOException e){e.printStackTrace ();} GHkSU;})
catch(Exception e){e.printStackTrace ();} %/s1ma6q
} }XUHP%
(Cq-8**dY
L=$P
//读取保存的下载信息（文件指针位置） WM#!X!Vo
private void read_nPos() L*_xu _F
{ g/E;OcFaO
try{ myo/}58Nv
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); s[g1ei9
int nCount = input.readInt(); ldxUq,p
nStartPos = new long[nCount]; 4@5<B
nEndPos = new long[nCount]; qHj4`&
for(int i=0;i<nStartPos.length;i++) $qvNv[
{ vD(;VeW[
nStartPos = input.readLong(); o]nQo?!
nEndPos = input.readLong(); 1{wy%|H\
} #: F)A_Y
input.close(); 8_uDxd
} ,"/_G
catch(IOException e){e.printStackTrace ();} R'F|z{8
catch(Exception e){e.printStackTrace ();} C$5v:Fk
} AkF1Hj
V6!oe^a7'
5!Guf?i
private void processErrorCode(int nErrorCode) ^,X+ n5q;m
{ Y5;:jYk#<_
System.err.println("Error Code : " + nErrorCode); D Lu]d$G
} v|hi;l@7E
qjWgyhL
;9^B# aTM
//停止文件下载 koUH>J:
public void siteStop() j_{gk"2:d`
{ n_!&Wr^CX
bStop = true; !=-l760
for(int i=0;i<nStartPos.length;i++) R38 w!6{
fileSplitterFetch.splitterStop(); 5E%W;$3Pb
d<whb2l
l0 1Lg6+S
} tpVtbh1)u
} `R^)<v*
//负责部分文件的抓取 MF1u8Yl:0
**FileSplitterFetch.java 4Qw!YI#40$
*/ \&cVcAg
package NetFox; A[b'MNsv
iX,Qh2(ig
E/am^ TO`
import java.io.*; <sPB|5Ak
import java.net.*; 2Zl65
:s4CWEd
_[<I&^%
public class FileSplitterFetch extends Thread { :O{:;X)
B}3s=+L@8
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String sURL; //File URL _Q7)FK
long nStartPos; //File Snippet Start Position u-?&~WA
long nEndPos; //File Snippet End Position ^{bP#f
int nThreadID; //Thread's ID ($3QjH_@
boolean bDownOver = false; //Downing is over #3qkG)
boolean bStop = false; //Stop identical UgUW4x'+
FileAccessI fileAccessI = null; //File Access interface m1frN#3
;eWVc;H
Qdtfi1_Y1
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException yyXJ_B
{ F:\y#U6"J
this.sURL = sURL; DF-og*V
this.nStartPos = nStart; JY /Cd6\
this.nEndPos = nEnd; c~>M7e(
nThreadID = id; b)df V=
fileAccessI = new FileAccessI(sName,nStartPos);//定位 ){6;o&CC:
} F<I-^BY)
J${wU@_%
f+)F-3
public void run() l5aQDkp}
{ a ZfX |
while(nStartPos < nEndPos && !bStop) pa.W-qyu
{ v!W,h2:J
Z'u`)jR
]o_ Ps|
try{ 4YdmG.CU
URL url = new URL(sURL); Lrz>00(*4
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); Zaq:l[%
httpConnection.setRequestProperty("User-Agent","NetFox"); `B^?Za,xN
String sProperty = "bytes="+nStartPos+"-"; 1W;+hXx
httpConnection.setRequestProperty("RANGE",sProperty); ^*Ca+22xO
Utility.log(sProperty); "--rz;+K
&oAuh?kTq
~DCw [y
InputStream input = httpConnection.getInputStream(); Q~`]0R159e
//logResponseHead(httpConnection); ^D\#*pIO
u<):gI
=m:0#&t,*
byte[] b = new byte[1024]; 5<&<61[A
int nRead; iS02uVmBZ
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) lPx4I
{ B:Msn)C~
nStartPos += fileAccessI.write(b,0,nRead); R_(A&,
//if(nThreadID == 1) =7Nm=5@
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); YsDn?pD@
} .\i9}ye
*-gS u
1!,lI?j,
Utility.log("Thread " + nThreadID + " is over!"); YMJ?t"
bDownOver = true; ='YR;
//nPos = fileAccessI.write (b,0,nRead); 5.idC-\
} N=-hXgX^
catch(Exception e){e.printStackTrace ();} rW!P~yk
} `y m^0x8
} /J1O{L
Av7bp[OD
:Bda]]Y=
//打印回应的头信息 2v yB[(
public void logResponseHead(HttpURLConnection con) HlLF<k~}
{ )7:2v1Xr]
for(int i=1;;i++) +d]}
{ S+_}=25
String header=con.getHeaderFieldKey(i); 6?z&G6
if(header!=null) ss |<\DE+
//responseHeaders.put(header,httpConnection.getHeaderField(header)); fq_6xs
Utility.log(header+" : "+con.getHeaderField(header)); &QLCij5:
else %0. o(U
break; c.,eIiL
} NhXTt!S6C
} `dMl5b
}8 fG+H.
,~%Qu~\
public void splitterStop() @UE0.R<
{ 0}-&v+
bStop = true; 3]M YHb
} E.t9F3
>O|hN`
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} uXyNj2(d.
i8+kc_8#d
-9\O$I-3
/* fw'$HV76
**FileAccess.java 78Nli/U
*//文件访问(定位，写) ,bKA]#(2
package NetFox; dGrOw)
import java.io.*; 0A/GWSmF
JPS L-j
WQ|d;[E
public class FileAccessI implements Serializable{ g=:%j5?.e
0+m"eGwTm
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 84cmPnaT
RandomAccessFile oSavedFile; `9kjYSd#E
long nPos; LdDkd(k
w[n|Sauy,
?,;|*A
public FileAccessI() throws IOException rX{QgyY&
{ mv)M9c,`
this("",0); PQlG!
} A|c :&i
kS[k*bN0
<~u.:x@ R
public FileAccessI(String sName,long nPos) throws IOException jgVra*
{ Xa Yx avq
oSavedFile = new RandomAccessFile(sName,"rw"); \V+$2 :A
this.nPos = nPos; (IAl$IP63s
oSavedFile.seek(nPos); t9zPJQlT}
} t&ztY] qh
^{zwIH2I]
Fx/9T2%=
public synchronized int write(byte[] b,int nStart,int nLen) Q{0-pHr}
{ fc+P`r
int n = -1; BB1'B-O
try{ ACU0
oSavedFile.write(b,nStart,nLen); 49@ pA-
n = nLen; t'Nu^_#
} u> %r(
catch(IOException e) EJNj.c-#
{ _(0!bUs>
e.printStackTrace (); fFqK.^Tn
} 4O[5,
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3Nsb@0
return n; a`~$6 "v
} !Z<GUblt
Vj:)w<],
s<sqO,!
} VCX})sp
__-rP
23U9+
/* c_kxjzA#
**SiteInfoBean.java mucY+k1>g
*/ MztT/31S
package NetFox; b!PN6<SI
yV$p(+KkS
u8~.6]Ae
public class SiteInfoBean { dGQy=T:
{>5z~OV
w44{~[0d4
private String sSiteURL; //Site's URL r&o%n5B
private String sFilePath; //Saved File's Path 5u~Ik c~
private String sFileName; //Saved File's Name DJr 8<u
private int nSplitter; //Count of Splited Downloading File WN?!(r<qA_
oQjh?vm
'"GdO;}&
public SiteInfoBean() C3G?dZKv2
{//nSplitter的缺省值为5 rfXM*h
//default value of nSplitter is 5 :*/<eT_
this("","","",5); 8W[QV
} R)nhgp(~
P2 !~}{-
]^8:"Ky'
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) WxWgY}`
{ L((z;y>q|
sSiteURL= sURL; BXZ( %tnY
sFilePath = sPath; P]yER9'
sFileName = sName; TN7kt]a2
this.nSplitter = nSpiltter; qWw@6VvoQ
eq(|%]a=
dK|MQ <
} NO`LSF
7M3q|7?
qAivsYN*
public String getSSiteURL() `vL R;D
{ ?rk3oa-
return sSiteURL; gS4K](KH |
} UF D_
yc_(L-'n
N]KqSpPh
public void setSSiteURL(String value) X H{5E4P
{ p KKn
sSiteURL = value; S8.nM}x
} xotq$r
K 2LLuS!
o'>jO.|
public String getSFilePath() &y3_>!L
{ XLEA|#
return sFilePath; qe`W~a9x
} dAym)
V [[B~Rs
{D1=TTr^
public void setSFilePath(String value) r/:9j(yxr
{ q^(A6W
sFilePath = value; I/XVo2Ee
} &b"PjtU.X
9I]*T
6CY_8/:zL
public String getSFileName() zT!JHG
{ c6BaC@2
return sFileName; hh:0m\@<
} 3zs~Y3M?i
J[VQ6fD%
Z|'tw^0e5
public void setSFileName(String value) wQPjo!FEX
{ *!C^L"i
sFileName = value; EBK\.[
} /vsQ <t;~
He">kJx
]7h&ZF
public int getNSplitter() TQID-I
{ i`Lt=)@&
return nSplitter; lYQcQ*-
} zLf^O%zN
4V43(G
2MtaOG2l&q
public void setNSplitter(int nCount) Nl;rg*@o
{ ,^AkfOY7"
nSplitter = nCount; K'1rS[^>R
} O?8G
} iCc@N|~
]C5JP~#z
)7c^@I;7
/* ``>WFLWTn
**Utility.java "z@qG]#5
*/ olK%TM[Y
package NetFox; mgH4)!Z*56
U{i9h6b"18
Hr96sN.R
public class Utility { J~n{gT<L
33"{"2==`
If]g6 B.=
public Utility() 0o`0Td
{ sx*(JM}Be
}tc,3>/
]J_Dn\
} ~w4aA<2Uq
gt}/C4|
//线程睡眠 $n(@hT>?
public static void sleep(int nSecond) {[)J~kC+
{ j_p.KF'[?
try{ <<4G GO
Thread.sleep(nSecond); N \A)P
} -pa.-@
catch(Exception e) "o=h /q5&
{ G8akMd]2
e.printStackTrace (); :q^g+Bu=
} a/`fJY6rR
} Z*s/%4On
k{"~G#GwP
//日志 ad i5h
public static void log(String sMsg) cs~ }k7><
{ %)\Cwl
System.err.println(sMsg); y(6&90cr
} ~g>15b3
*~2jP;$
p*NC nD*
public static void log(int sMsg) p~Dm3^Y
{ %aL>n=$
System.err.println(sMsg); MeP U`M--
} Ldt7?Y(V(
} "Z}0A/y
6~$<
wyAqrf
/* CcAsJX~_
**TestMethod.java _Y\@{T;^Zb
*/ ]DC]=F.
package NetFox; >Z<ym|(T*
?R"5 .3
'>'h7F=tY
public class TestMethod { YVu8/D@ o
t6-c{ZX>A
%z8@;
public TestMethod() [>Q{70 c[
{ ///xx/weblogic60b2_win.exe CdTmL{Y1
try{ Ra~n:$tg2
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); Z4hP
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); b39;Sv|#
SiteFileFetch fileFetch = new SiteFileFetch(bean); hTVN`9h7
fileFetch.start(); uVOpg]8d
} HzbO#)Id-I
catch(Exception e){e.printStackTrace ();} 0SvPyf%AC
\ov>?5
b'vJPv~hI
} \Xxx5:qM
5:n&G[Md
*p.ELI1IC
public static void main(String[] args) jGt'S{
{ o~es>;
new TestMethod(); Av+ w>~/3
} :p8JO:g9
} )#*c|.
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