http断点续传简单实现（java)

亚文隆

级别: 经院学前班

发帖: 8

铜板: 1641

人品值: 95

贡献值: 0

交易币: 0

好评度: 8

信誉值: 0

金币: 0

所在楼道

只看楼主更多操作楼层直达

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)); =%p%+F@RlW
} 9#:b+Amzz
for(int i=0;i<nEndPos.length-1;i++) !xU1[,9
{ ;TaR1e0
nEndPos = nStartPos[i+1]; N;<.::x
} yfBVy8Sm
nEndPos[nEndPos.length-1] = nFileLength; \DP*?D_}?
} Z9:erKT
} )2@_V %
%J*z!Fe8s
6} DGEHc1
//启动子线程 CM}1:o<<N
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; >s@*S9cj:
for(int i=0;i<nStartPos.length;i++) pEc|h*p8
{ 8PWx>}XPt
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), ?tWcx;h:>
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), <A"T_Rk
nStartPos,nEndPos,i); >^cP]gGY
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); %SV5PO@
fileSplitterFetch.start(); A!([k}@=j
} CNC3">Dk~9
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), {-(}p+;z
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); +*dG'U6
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", MXSN <
nEndPos = " + nFileLength); W/(D"[:l%
// fileSplitterFetch[nPos.length-1].start(); 3Un{Q~6h
[dm&I#m=
<kQ 5sG
//等待子线程结束 rJ LlDKP-(
//int count = 0; #cG7h(!
//是否结束while循环 XcoV27
boolean breakWhile = false; U@W3x@
zEG6T*
]0`*gKA
while(!bStop) [dG&"%5vD
{ Y\7>>?
write_nPos(); w2-:!,X
Utility.sleep(500); <ptgFR+
breakWhile = true; j2V"w&>b}
gy|L!_1Z8
^;";fr Vw
for(int i=0;i<nStartPos.length;i++) 4)L(41h
{ oCE=!75
if(!fileSplitterFetch.bDownOver) Vy]y73~
{ Vej [wY-c
breakWhile = false; pwg$% lv
break; #cB=](N
} VO_! +
} !.(Kpcrg
if(breakWhile) uSZCJ#'G
break; dP>~ExYtm
6S#Y$2 P
^ olaq(z
//count++; N=1zhI:VaQ
//if(count>4) AJk0jh\.j%
// siteStop(); P5u Y1(
} dGxk ql
r)ni;aP
mR3)$!
System.err.println("文件下载结束！"); l@ +lUx8
} m3Mo2};?
catch(Exception e){e.printStackTrace ();} 8(yZX4OH>
} VMry$
g"k1O
Lk?%B)z
//获得文件长度 Y ^s_v_s
public long getFileSize() qPh @Bl3
{ A1b</2
int nFileLength = -1; .hBq1p
try{ G?:{9. (
URL url = new URL(siteInfoBean.getSSiteURL()); b2}>{Li0
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); W62 $ HI
httpConnection.setRequestProperty("User-Agent","NetFox"); v"nN[_T
Bw;gl^:UG
.YV{wL@cB
int responseCode=httpConnection.getResponseCode(); *&WkorByW
if(responseCode>=400) -6 WjYJx
{ _|f1q
processErrorCode(responseCode); 4&r5M
return -2; //-2 represent access is error K U 2LJ_~Y
} )?5027^
D{-h2=V
RMinZ}/
String sHeader; s)Gnj;
IM.sW'E
)7$1Da|.
for(int i=1;;i++) p`/"e<TP
{ J1i{n7f=@
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); pbfIO47ZC
//Utility.log(in.readLine()); f`ro{p
sHeader=httpConnection.getHeaderFieldKey(i); `pMI@"m
if(sHeader!=null) h |Ofi
{ a`c#- je
if(sHeader.equals("Content-Length")) 4LG[i}u.N
{ =>?;Iv'Z
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); j@N z
break; bjn: e!}
} #[ei/p
} /_WAF90R?
else eUBf-xA
break; k|C~qe3E
} icO$9c
} }BF!!*
catch(IOException e){e.printStackTrace ();} bQU{)W
catch(Exception e){e.printStackTrace ();} F$L2bgQR?'
1NHiW v
&zuPt5G|
Utility.log(nFileLength); D4@).%
:;Lt~:0b~
2C6o?*RjyY
return nFileLength; mLEJt,X
} myq@X(K
s9[?{}gd
Dno]N
//保存下载信息（文件指针位置） NCrNlHIF
private void write_nPos() Cz1Q@<)
{ s ;3k#-w
try{ Hw0S/ytY
output = new DataOutputStream(new FileOutputStream(tmpFile)); |`T$Iq
output.writeInt(nStartPos.length); =`MxgK +
for(int i=0;i<nStartPos.length;i++) ae%Bl[
{ u+5&^"72,
// output.writeLong(nPos); ?;GbK2\bj
output.writeLong(fileSplitterFetch.nStartPos); \d'>Ky;GD
output.writeLong(fileSplitterFetch.nEndPos); /9SEW!E
} Y ~TR`y
output.close(); Z\YCjs%
} 7 XNZEi9o
catch(IOException e){e.printStackTrace ();} 7 KuUV!\h`
catch(Exception e){e.printStackTrace ();} ~FP4JM,y6
} ]\~s83?X
(vR9vOpJ
8v<802
//读取保存的下载信息（文件指针位置） F"-u8in`
private void read_nPos() dd+hX$,
{ H{)DI(,Y^P
try{ YkN0,6
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); w3n6md
int nCount = input.readInt(); `49:!M$i
nStartPos = new long[nCount]; OO?;??
nEndPos = new long[nCount]; 1>c^-"#e^
for(int i=0;i<nStartPos.length;i++) J-UqH3({Z,
{ \m xi8Z w
nStartPos = input.readLong(); YW14X
nEndPos = input.readLong(); x?"+Or.h
} dguN<yS-E
input.close(); ?&`PN<~2z
} MyZ5~jnr\
catch(IOException e){e.printStackTrace ();} <r>1W~bp.q
catch(Exception e){e.printStackTrace ();} \CU-a`n
} .](~dVp%~
@u>:(9bp
gzMp&J
private void processErrorCode(int nErrorCode) U/#X,Bi~
{ wsKOafrV
System.err.println("Error Code : " + nErrorCode); gAudL)X
} ^)nIf)9}7
r!N> FE
C8Oh]JF4d
//停止文件下载 1zcaI^e#
public void siteStop() $etw'c0
{ +s j2C
bStop = true; .),Fdrg
for(int i=0;i<nStartPos.length;i++) ykS-5E`
fileSplitterFetch.splitterStop(); DqJzsk'd3
"C]v
c]/X >8;
} B*@0l:
} F(;=^w
//负责部分文件的抓取 e"d-$$'e
**FileSplitterFetch.java &cpqn2Z
*/ -=InGm\Y
package NetFox; z%q)}$O
<#ng"1J
p 2>\
import java.io.*; W9rmAQjn
import java.net.*; &*Z"r*
Z?f-_NHg
9 df GV!Z
public class FileSplitterFetch extends Thread { gq7l>vT.
;u?L>(b
g=na3^PL6
String sURL; //File URL (|2:^T+
long nStartPos; //File Snippet Start Position t"$#KP<
long nEndPos; //File Snippet End Position 1YtbV3
int nThreadID; //Thread's ID f q&(&(|
boolean bDownOver = false; //Downing is over yog(
boolean bStop = false; //Stop identical J$^"cCMr
FileAccessI fileAccessI = null; //File Access interface h( DmSW
N|2PW ~,
&5y|Q?
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException adn2&7H
{ `'E(L&
this.sURL = sURL; zHX7%x,Cq
this.nStartPos = nStart; h]vuBHJ}
this.nEndPos = nEnd; 1>=]lMW
nThreadID = id; >c@jl
fileAccessI = new FileAccessI(sName,nStartPos);//定位 Tr.u'b(
} mhgvN-? "h
M,vCAZ
ZK4d;oa",
public void run() 7PbwCRg
{ o_sb+Vn|
while(nStartPos < nEndPos && !bStop) 4*&2D-8<K
{ Tg@:mw5
7Tc^}Q
cz41<SFL
try{ "=Cjm`9~j
URL url = new URL(sURL); @:/H)F^x
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); &a'mh
httpConnection.setRequestProperty("User-Agent","NetFox"); j" 5 +"j
String sProperty = "bytes="+nStartPos+"-"; 0TqIRUz "C
httpConnection.setRequestProperty("RANGE",sProperty); ~,Kx"VK
Utility.log(sProperty); cB6LJ}R
7S{yKS
pS~=T}o
InputStream input = httpConnection.getInputStream(); {%D4%X<
//logResponseHead(httpConnection); IP!`;?T=
W.(Q u-AE(
%$&_!
byte[] b = new byte[1024]; WS.lDMYE7
int nRead; cS%;JV>C
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) a] P0PH~
{ xz-?sD/xe
nStartPos += fileAccessI.write(b,0,nRead); gs(ZJO1 /L
//if(nThreadID == 1) 6J<R;g23R]
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); *o=[p2d"X
} T2_b5j3i
E/hO0Ox6
Ce:w^P+
Utility.log("Thread " + nThreadID + " is over!"); $#-O^0D
bDownOver = true; @6Z6@Pq(xQ
//nPos = fileAccessI.write (b,0,nRead); b"y4-KV
} +' SG$<Xv
catch(Exception e){e.printStackTrace ();} &<EixDi4q
} &&7&/
} 07G'"=
r<[G~n
hf:\^w
//打印回应的头信息 T*%O\&'r
public void logResponseHead(HttpURLConnection con) v+~O\v5Q
{ "I QM4:
for(int i=1;;i++) x~E\zw
{ 0D/7X9xg9+
String header=con.getHeaderFieldKey(i); g~XR#vl$
if(header!=null) |qf ef&
//responseHeaders.put(header,httpConnection.getHeaderField(header)); GK[9Cm"v
Utility.log(header+" : "+con.getHeaderField(header)); pHKc9VC
else hm0MO,i"
break; ,rX|_4n*
} ~Kt2g\BSok
} 9vBW CCf
,7)zavA
Ud_0{%@
public void splitterStop() xk7VuS*
{ \;1nEjIA
bStop = true; m U= 3w
} 9h"3u;/,
\.]C`ocD
h\4enu9[RL
} eyy%2>b
L\q-Z..
y$9XHubu
/* yeLd,M/I
**FileAccess.java S;tvt/\!Z
*//文件访问(定位，写) _FkH;MGWS
package NetFox; IM_SZs
import java.io.*; M%OUkcWCk
ZyV^d3F@$
P}w0=
public class FileAccessI implements Serializable{ 2>g!+p Ox
MaZVGrcC
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 hVNT
RandomAccessFile oSavedFile; QTU$mC]
long nPos; 8{)N%r
;P^}2i[q>[
-YS9u[
public FileAccessI() throws IOException :464~tHI[`
{ 1]"S?
this("",0); A#gy[.Bb
} eC@b-q
xmejoOF
CUx-k|\
public FileAccessI(String sName,long nPos) throws IOException .ZupsS9l
{ Hq|{Nt%Q
oSavedFile = new RandomAccessFile(sName,"rw"); 5Vr#>W
this.nPos = nPos; 'VV"$`Fu"
oSavedFile.seek(nPos); <CWOx&hr
} K@?K4o
{a,U{YJ\H
1aezlDc*
public synchronized int write(byte[] b,int nStart,int nLen) \CBL[X5tr
{ S<g~VK!Tt
int n = -1; t\O#5mo
try{ SmV}Wf
oSavedFile.write(b,nStart,nLen); (8(P12l
n = nLen; <m*j1|^{t
} `We?j7O
catch(IOException e) 6 )lWuY]e
{ 'OU`$K7n
e.printStackTrace (); S_;m+Ytg
} \*Z:w3;r
5k;}I|rg%
NYeL1h)l
return n; dvLL~VP
} =00sB
_Nf%x1m5s
=(Y+u
} [f?x,W~
0y%s\,PsT
S~B{G T\M
/* Zbf~E {
**SiteInfoBean.java ,Y@4d79
*/ IO"q4(&;P4
package NetFox; yY!@FGsA
o4,9jk$
&(NW_<(
public class SiteInfoBean { 'JJ :
of>H&G)@
A`V:r2hnb
private String sSiteURL; //Site's URL ~n%]u! 6
private String sFilePath; //Saved File's Path cK75Chsu
private String sFileName; //Saved File's Name V=E5pB`Pr
private int nSplitter; //Count of Splited Downloading File j3fq}>=
B %
AIw~@*T
public SiteInfoBean() |5*:ThC[
{//nSplitter的缺省值为5 <W/YC2b
//default value of nSplitter is 5 #(-?i\i
this("","","",5); oTveY
} ;oOv~YB7H
EV_u8?va
/a\]Dwj5
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) k;HI-v
{ Dk}txw}#
sSiteURL= sURL; 5KW n>n
sFilePath = sPath; 6>[J^k%~w)
sFileName = sName; CIQ9dx7>
this.nSplitter = nSpiltter; G5UNW<P2C
bLO^5`6
3A3WD+[L
} ygxaT"3"=
RggO|s+0;
|&~);>Cq2
public String getSSiteURL() wvH*<,8Vq
{ '&Tz8.jp~
return sSiteURL; ~/!jKH7`j
} 7lAnGP.;
q5.5%W
\7Fp@ .S3
public void setSSiteURL(String value) 5Z[HlN|-!
{ $SU<KNMZ
sSiteURL = value; ]T%wRd5&-
} /brHB @$
'Ecd\p
&7KX`%K"D
public String getSFilePath() ~uuM0POo
{ ZSn6JV'g
return sFilePath; z=TuUl@
} v&xhS yZ
zI_pP?4;.q
SA~oGgk=P
public void setSFilePath(String value) ]C>h_,EZc
{ nzKlue
sFilePath = value; j^D/,SW
} 7 ;x to =
vZIx>
:~~\{fm
public String getSFileName() :-j/Y'H_
{ /Tp>aW%}"
return sFileName; QLZ%m$Z
} fAD {sg
(n2=.9k!
[L?WM>]%
public void setSFileName(String value) jNAboSf2Y
{ r:,"k:C
sFileName = value; FwDEYG
} .FvIT]k-
<\L=F8[
LF!S`|FF
public int getNSplitter() MYUL y2)
{ dDqT#N?Y
return nSplitter; z*WQ=l2
} XpdjWLO]C<
$~T|v7Y%
2l+t-
public void setNSplitter(int nCount) xsg55`
{ kj`h{Wc[)
nSplitter = nCount; T>m|C}yy
} 1fV\84m^
} -\g@s@5
{QIdeB[
D}?JX5.
/* wArzMt}[
**Utility.java OJs s
*/ _j]vR
package NetFox; _+qtH< F/
V/J-zH&
4x" je
public class Utility { R'aA\k-
8-)@q|
}SGb`l
public Utility() CMYkxU
{ `W%R
B{NGrC`5)
1Pd2%
} l6T5]$
?8$h%Ov-
//线程睡眠 .7n`]S/
public static void sleep(int nSecond) P,7beHjf
{ $WbfRyXi7'
try{ /?:q9Wy
Thread.sleep(nSecond); 9<"l!noy
} 7/FF}d
catch(Exception e) :qvaI,
{ eX o@3/
e.printStackTrace (); 0y=lf+xA*
} :Q>{Y
} )IGx3+I ,
^%/d]Zwb
//日志 b+THn'2
public static void log(String sMsg) Og"\@n
{ 3Oe\l[?$;
System.err.println(sMsg); @BqSu|'Du,
} kDWvjT
n<MreKixE
:SVWi}:Co1
public static void log(int sMsg) 8z*/J=n
{ %>,Kd6bdg
System.err.println(sMsg); rq^VOK|L
} Z|zT%8.8N
} HeM-
'dcO-A:>
01o,9_|FL
/* |3 v+&eVi
**TestMethod.java 3NgyF[c
*/ +'9eo%3O
package NetFox; 6g'+1%O
]}BT'fky#
]PZ\N~T
public class TestMethod { .q9i10C
F vHd`
T :X A
public TestMethod() >FReGiK$T
{ ///xx/weblogic60b2_win.exe E7|P\^}m(f
try{ RU,!F99'1
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); )5ISkbsxD
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); 9C\@10D
SiteFileFetch fileFetch = new SiteFileFetch(bean); i,y7R?-K
fileFetch.start(); ;Y`k-R:E6A
} X8(WsN
catch(Exception e){e.printStackTrace ();} (W_U<~`t
iFaC[(1@a
z229:L6"
} w&LL-~KI+
R5MY\^H/A
{&.?u1C.\
public static void main(String[] args) A{a`%FAV
{ w-?Cg8bq<
new TestMethod(); x-@6U
} ZVz`-hB
} f}+8m .g2
点击下载更多相关资料