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)); }6gum
} I.it4~]H
for(int i=0;i<nEndPos.length-1;i++) %Z*N /nU
{ w<Bw2c
nEndPos = nStartPos[i+1]; OR}+)n{
} bu{dT8g'U
nEndPos[nEndPos.length-1] = nFileLength; V=<AI.Z:w
} g]E3+:5dk
} F |aLF{
9 dK`
!C ZFbz~:
//启动子线程 }=|plz}
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; Ey%KbvNv
for(int i=0;i<nStartPos.length;i++) ]KQQdr
{ Re*_Dt=r
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), u:H:N]
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), e xkPu-[W
nStartPos,nEndPos,i); CZf38$6X
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); Z1.v%"/(
fileSplitterFetch.start(); } L_Zmi$
} \\;y W~
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), [_: GQ
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); 8RQv
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", $laUkD#vz
nEndPos = " + nFileLength); ;vy<!@Y;8
// fileSplitterFetch[nPos.length-1].start(); J,\e@
M0$E_*
je%D&ci$
//等待子线程结束 -b|"%e<'
//int count = 0; R2JPLvs
//是否结束while循环 J$lfI^^
boolean breakWhile = false; %M:$ML6b<
fk!9` p'
]E6r)C
while(!bStop) *K BaKS
{ <v=s:^;C0
write_nPos(); p(nEcu
Utility.sleep(500); y+KAL{AGK
breakWhile = true; uW2 q\
fXh{_>
h/6^>setz
for(int i=0;i<nStartPos.length;i++) + )[@
{ GWv i
if(!fileSplitterFetch.bDownOver) LqNyi
{ F x^X(!)~]
breakWhile = false; >dgz/n?:v
break; Vcnc=ct
} PkLNIp1
} J 5xMA-
if(breakWhile) tq?a3
break; 7C R6ew~
1jO%\uR/
F)v
//count++; .R l7,1\
//if(count>4) *F!1xyg
// siteStop(); ,RW`9+gx
} cL][sI
pC #LQ
7O:g;UI#
System.err.println("文件下载结束！"); N,l"9>CF
} M8/:PmR<
catch(Exception e){e.printStackTrace ();} XUnw*3tPJ
} T#wG]DH;
Cc;8+Z=a?G
vPc*x5w-
//获得文件长度 $HtGB]
public long getFileSize() 9Q!Z9n"8~)
{ tzv4uD]
int nFileLength = -1; _GrifGU\
try{ >|yP`m
URL url = new URL(siteInfoBean.getSSiteURL()); :(wFNK/0{
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); K/j u=>
httpConnection.setRequestProperty("User-Agent","NetFox"); zWH)\>X59
K:GEC-
[YZgQ
int responseCode=httpConnection.getResponseCode(); @$'pMg
if(responseCode>=400) SN]g4}K-
{ P$Oj3HD LM
processErrorCode(responseCode); k61mRO
return -2; //-2 represent access is error x/wgD'?
} DR,7rT{$
Cs y,3XG
h(<>s#=E
String sHeader; P|Gwt&
0{ ~2mggh
79D~Mau#
for(int i=1;;i++) 3u&,3:
{ ' QMcQvU
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); G]N3OIw&8
//Utility.log(in.readLine()); ^i_+ugJX
sHeader=httpConnection.getHeaderFieldKey(i); RRV%g!
if(sHeader!=null) J7^UQ
{ g(;OUkj$Zp
if(sHeader.equals("Content-Length")) t$wbwP
{ 8?Ju\W
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); T&+3Xi:
break; {Dk!<w I)
} cz{`'VN}`
} &(A#F[ =0
else )GAlj;9A$
break; V7r_Ubg@K
} ydo9 P5E
} 1[8^JVC>6
catch(IOException e){e.printStackTrace ();} i?;#ZNh
catch(Exception e){e.printStackTrace ();} s)`(@"{
bxtH`^
{sGEopd8]q
Utility.log(nFileLength); ..X_nF
"YY<T&n
Yj/o17
return nFileLength; ",D!8>=s
} DXI4DM"15I
8FMxn{k2
EJ#I7_
//保存下载信息（文件指针位置） q,O_y<uw
private void write_nPos() 4\u`MR
{ yn_f%^!G
try{ -0#"<!N
output = new DataOutputStream(new FileOutputStream(tmpFile)); z!O;s ep?/
output.writeInt(nStartPos.length); 6V%}2YE?X
for(int i=0;i<nStartPos.length;i++) `bfUP s
{ }DS%?6}Sy
// output.writeLong(nPos); GIH{tr1:<
output.writeLong(fileSplitterFetch.nStartPos); wT\BA'VQ
output.writeLong(fileSplitterFetch.nEndPos); l<GN<[/.+
} 7@%qm|i>w
output.close(); boGdZ2$h4
} |1(x2x%}D^
catch(IOException e){e.printStackTrace ();} |+W{c`KL
catch(Exception e){e.printStackTrace ();} -X!<$<\y;
} ;!A8A4~nu
I`X!M!dB)
[`b,SX x
//读取保存的下载信息（文件指针位置） ]tN)HRk1
private void read_nPos() N6"sXwm
{ zGR,}v%%
try{ -dA9x~o
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); R/Bjc}J'
int nCount = input.readInt(); $cHU,
nStartPos = new long[nCount]; kY\faWuR
nEndPos = new long[nCount]; Nh}-6|M
for(int i=0;i<nStartPos.length;i++) ))f@9m
{ g:ky;-G8b
nStartPos = input.readLong(); -0kMh.JYR
nEndPos = input.readLong(); $<nRW*d
} %W\NYSm
input.close(); hmo4H3g!N
} L%/>Le}VX
catch(IOException e){e.printStackTrace ();} W+1nf:AI.
catch(Exception e){e.printStackTrace ();} PL{lYexJ
} ?D _4KFr
cM'MgX9
3 0[Xkz
private void processErrorCode(int nErrorCode) oSD=3DQ;
{ iL);bv W
System.err.println("Error Code : " + nErrorCode); 1>rQ).eT
} !DFTg4xb
v#&;z_I+
Y4 z
//停止文件下载 j0}wv~\
public void siteStop() R9R~$@~G
{ ~deS*
bStop = true; syW[uXNLZ
for(int i=0;i<nStartPos.length;i++) x5uz$g
fileSplitterFetch.splitterStop(); X^N6s"2
J FnE{
ocWl]h].
} a<q9~QS
} ,--#3+]XU
//负责部分文件的抓取 f}(4v1T
**FileSplitterFetch.java @y7KP$t
*/ IC'+{3.m8
package NetFox; 'Xwv,
~6kF`}5
n'^`;-
import java.io.*; <Hr<QiAK
import java.net.*; #1E4 R}B
yKl^-%Uq<
H!]&"V77
public class FileSplitterFetch extends Thread { -%MXt
S8dfe~|7:
/B?wn=][
String sURL; //File URL aC2Vz9e
long nStartPos; //File Snippet Start Position 01-rBto$
long nEndPos; //File Snippet End Position h<3b+*wYJC
int nThreadID; //Thread's ID Nmz5:Rq
boolean bDownOver = false; //Downing is over j% 7Gje[
boolean bStop = false; //Stop identical ,+`r2}N \/
FileAccessI fileAccessI = null; //File Access interface #Mn?Nn
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onSt%5{P%X
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException =@M9S
{ j[:70%X
this.sURL = sURL; VVch%
this.nStartPos = nStart; BedL `[,
this.nEndPos = nEnd; 51|s2+GG
nThreadID = id; "rLm)$I
fileAccessI = new FileAccessI(sName,nStartPos);//定位 e8 ]CB
} F]6G<6T[
I2CI9,0
jy.L/s
public void run() 'XKfKv >;
{ A"M;kzAfHM
while(nStartPos < nEndPos && !bStop) z_xy*Iif
{ 9_5>MmiB
6jc5B#
b}Gm{;s!
try{ L]z8'n,
URL url = new URL(sURL); YT!iI
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); @-S7)h>~
httpConnection.setRequestProperty("User-Agent","NetFox"); :2c(.-[`
String sProperty = "bytes="+nStartPos+"-"; 6/L[`n"G
httpConnection.setRequestProperty("RANGE",sProperty); _VdJFjY?zc
Utility.log(sProperty); 8Gy]nD
@4*eH\3
vzI>:Bf
InputStream input = httpConnection.getInputStream(); i=n;rT
//logResponseHead(httpConnection); 9?ll(5E
A]0R?N9wb_
H4 O"^#5
byte[] b = new byte[1024]; v1yB
int nRead; [C4{C4TX
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) `;}qjm0a
{ nw/g[/<;
nStartPos += fileAccessI.write(b,0,nRead); Zc_F"KJL
//if(nThreadID == 1) vo }4N[]Sb
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); Kn$E{F\
} <`SA>P
P??P"^hU
Vbp@n
Utility.log("Thread " + nThreadID + " is over!"); }|Q\@3&
bDownOver = true; n%36a(] t
//nPos = fileAccessI.write (b,0,nRead); <(Ar[Rp
} 2 oL$I(83
catch(Exception e){e.printStackTrace ();} 5g-1pzP9
} ],!}&#|
} 3t9+YdNKU
ZKt{3P
h#UPU7;
//打印回应的头信息 Z<d=v3q
public void logResponseHead(HttpURLConnection con) \\R<HuTY
{ W7|nc,i0\
for(int i=1;;i++) 4>d]0=x
{ 8u)>o* :
String header=con.getHeaderFieldKey(i); >?JUGXAi'{
if(header!=null) )UU`uzU;u
//responseHeaders.put(header,httpConnection.getHeaderField(header)); B=W#eu <1
Utility.log(header+" : "+con.getHeaderField(header)); 3'L =S
else u8?$W%eW
break; g; -3
} Jb> X$|N'%
} Xbx=h^S
mvpcRe <
Fg p|gw4
public void splitterStop() t3.;qDy
{ \25EI]
bStop = true; :&&s*_
} 5,4" CF$
J(]b1e
M*T!nwb
} :_HdOm
/z!y[ri+J
J0&-UnJ
/* (g[WZB3x
**FileAccess.java #G(ivRo
*//文件访问(定位，写) EY !o#m
package NetFox; l2M(
import java.io.*; u"7!EhX&
L^CB#5uG
AwuhFPG
public class FileAccessI implements Serializable{ w#BT/6W&G
ODRy
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 2H8\P+
RandomAccessFile oSavedFile; cna%;f.
long nPos; Ed0}$b
nZYO}bv\
aEa.g.SZ
public FileAccessI() throws IOException s4f{ziLp
{ "tJ[M
this("",0); t}}Ti$$>
} FnOahLS
a)S6Z
4k{xo~+%,
public FileAccessI(String sName,long nPos) throws IOException %'. x vC
{ ,bM):
oSavedFile = new RandomAccessFile(sName,"rw"); q3v5gz^t
this.nPos = nPos; l%0-W
oSavedFile.seek(nPos); 2Kr8#_) 0
} 7;.Iat9gMf
z&#^9rM"
fWIWRsy%
public synchronized int write(byte[] b,int nStart,int nLen) lOb(XH9
{ X<W${L$G
int n = -1; b ~]v'|5[
try{ V4Qy^nn1
oSavedFile.write(b,nStart,nLen); "85)2*+
n = nLen; e1V1Ae
} qOQ8a:]?
catch(IOException e) H;AMRL o4z
{ ]d{lS&PRlg
e.printStackTrace (); `25<;@
} )3|a_
LtUw
q!><:"#[G
return n; 5mL4Zq"
} *(wxNsK
Ue`Y>T7+!
&+hk5?c /
} F4V) 0)G
+_*iF5\
M=3w
/* !"hzGgOOX
**SiteInfoBean.java vq3:N'
*/ 5L7nEia'
package NetFox; 5K&A2zC|
}2c&ARQ.m>
mL#$8wUdt{
public class SiteInfoBean { /c!^(5K fT
noB8*n0
I+3=|Vef
private String sSiteURL; //Site's URL fX\y/C
private String sFilePath; //Saved File's Path qv:DpK
private String sFileName; //Saved File's Name o7PS1qcya<
private int nSplitter; //Count of Splited Downloading File ;/ |tU o$
|h/{qpsu
K0I.3|6C
public SiteInfoBean() >s.y1Vg~C
{//nSplitter的缺省值为5 K2v[_a~@
//default value of nSplitter is 5 ?-0, x|ul
this("","","",5); E 8$S0u;`
} y5^OD63s
&b%2Jx[+
#tw_`yh
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) bl10kI:F
{ r/)ZKO,
sSiteURL= sURL; <4zSh3
sFilePath = sPath; fceO|mSz_
sFileName = sName; qf@P9M
this.nSplitter = nSpiltter; vwa*'C
Bk5 ELf8pL
W|sU[dxZ
} >xF&>SDC
qq?o^_^4
aN,?a@B
public String getSSiteURL() t-}IKrbv
{ z7P~SM
return sSiteURL; Qk|+Gj
} J5<16}*
KCp9P2kv.
x",ktE>9
public void setSSiteURL(String value) rmWsob
{ CQ{{J{pU"
sSiteURL = value; Vvfd?G"
} zyP/'X_~:
_sL;E<)y(
U(OkTJxv+
public String getSFilePath() tt6GtYrC 1
{ 2BT+[
return sFilePath; {(tR<z)
} /9Qr1@&v
COBjJ3
/3sX>Rj
public void setSFilePath(String value) '0o^T 7C
{ 6rCUq
sFilePath = value; *]Cyc<
} Rz&}e@stl
,Qo:]Mj
:v$)Z~
public String getSFileName() ,iZKw8]f
{ c7WOcy@M
return sFileName; ,":_CY4(
} t56PzT'M
{%&04yq+
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public void setSFileName(String value) 2#/sIu-L
{ 4+p1`
sFileName = value; ^q%f~m,O<
} nYvkeT
Lm1JiPs d
eIf-7S]m
public int getNSplitter() U17=/E
{ Dk2Zl
return nSplitter; ~,8#\]xR
} q@wX=
kK:Wr&X0H
E7w^A
public void setNSplitter(int nCount) . _Jypk8
{ cbzS7q<)
nSplitter = nCount; C}L2'l,
} *&+zI$u(
} W(-son~I
e(&u3 #7Nn
a^[s[j#^,
/* M[-/&;`f@
**Utility.java bB*cd!7y
*/ uGYH4
package NetFox; OI6m>XH?
t!B,%,Dp
^\\9B-MvY
public class Utility { =`CK`x
#i.BOQxS
gt~u/Z%
public Utility() pQ4HX)<P
{ ~[BGKqh
WZTv
'[_.mx|cd`
} FBzsM7]j
`@u9 fx.
//线程睡眠 n%02,pC6,
public static void sleep(int nSecond) N1x~-2(
{ V;Ln|._/t
try{ [`bK {Dq2
Thread.sleep(nSecond); E2`9H-6e
} {aK3'-7
catch(Exception e) )}_}D+2
{ l>(*bb1}b
e.printStackTrace (); bhsCeH
} 4TiHh
} g~9b_PY9
$d.Dk4.ed
//日志 >-w#&T &K
public static void log(String sMsg) B=}QgXg
{ KO"+"1 .
System.err.println(sMsg); !i@A}$y
} OW!y7
Df(+@L5!
SFFJyRCz
public static void log(int sMsg) E4_,EeC#
{ cw0uLMqr`
System.err.println(sMsg); DC_k0VBn
} :TV`uUE
} LA/Qm/T
QXy=|
~9;udBfwF
/* fZnq5rTk"
**TestMethod.java 0[7"Lhpd
*/ XCXX(8To0=
package NetFox; "zqa:D26
[l<&eI&ln
A2P.5EN
public class TestMethod { Cj YI*
2)QZYgfh
5rQu^6&
public TestMethod() KAu>U3\/
{ ///xx/weblogic60b2_win.exe >5Y.
try{ G2P:|R
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); lJx5scN[
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); =&FaMR2
SiteFileFetch fileFetch = new SiteFileFetch(bean); t"MrrK>T
fileFetch.start(); #|=lU4Bf
} g{2~G6%;0
catch(Exception e){e.printStackTrace ();} G6JP3dOT
~HKzqGQy>
:wUi&xw
} 2{oQ
oMoco tQ;$
z('t#J!b
public static void main(String[] args) |~rKDc
{ {yd(n_PqY
new TestMethod(); qc';<
} ^^a%Lz)U
} xjrL@LO#
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