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)); ND)M3qp2(
} BP7<^`i&
for(int i=0;i<nEndPos.length-1;i++) &;uGIk>s
{ rm7*l<v6
nEndPos = nStartPos[i+1]; W#oEF/G
} @E&X&F%
nEndPos[nEndPos.length-1] = nFileLength; (+]Ig> t
} +#i,87
} hs -}:^S`
DbPBgD>Q
3V8j>&
//启动子线程 qB`0^V
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; L@^!(
for(int i=0;i<nStartPos.length;i++) -Y!=Iw 4
{ b{yH4)O
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), s525`Q;
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), 6w .iEb
nStartPos,nEndPos,i); B4M'Er{v
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); mtHi9).,y|
fileSplitterFetch.start(); ;r2b@x:<_
} &`\kb2uep
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), <)0LwkFtB
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); 1nX68fS.9
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", [3bwbfHhi
nEndPos = " + nFileLength); @Z1?t%1
// fileSplitterFetch[nPos.length-1].start(); 37<GG)
O+3D 5*
JqH.QnKcv
//等待子线程结束 z;@S_0M,Z
//int count = 0; U%SNROj
//是否结束while循环 z<C~DH
boolean breakWhile = false; f|HgLFx
*^&iw$Qx3
"}azC|:5
while(!bStop) s#8{:ko
{ xX67bswG
write_nPos(); ^,\se9=(
Utility.sleep(500); |Y,X=Ed
breakWhile = true; [+[fD
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nh_xbo5L[
for(int i=0;i<nStartPos.length;i++) F\$}8,9
{ :d/:Ga5v!
if(!fileSplitterFetch.bDownOver) N'1[t
{ JjL0/&
breakWhile = false; s9)8{z
break; QH56tQq
} \?Oa}&k$F8
} 8B(Q7Qj
if(breakWhile) #onfac-3
break; s!zr>N"
vN[m5)aT
~o\]K
//count++; b9!J}hto,
//if(count>4) Wug?CFX+T
// siteStop(); _[6+FdS],
} X$Qi[=L
L``mF(R^
1</t #r
System.err.println("文件下载结束！"); 6(RqR
} @C6DOB
catch(Exception e){e.printStackTrace ();} NhaeAD $e
} L&F\"q9q71
b+fy&rk@-
UM;bVf?
//获得文件长度 y#SD-#I-
public long getFileSize() REe%>|
{ GVPEene
int nFileLength = -1; !N2 n@bo
try{ 4rCqN.J
URL url = new URL(siteInfoBean.getSSiteURL()); v6(l#,
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); vnT
httpConnection.setRequestProperty("User-Agent","NetFox"); AZm)$@e)
0Nzv@g{3
ZtZV:re=
int responseCode=httpConnection.getResponseCode(); hQrsZv:Q
if(responseCode>=400) kT3;%D^
{ rAi!'vIE
processErrorCode(responseCode); 9n2%7dLQ*
return -2; //-2 represent access is error eh# (}v
} `Y9}5p
rs)aEmvC
Y .X-8
String sHeader; *fyEw\`a
&Fr68HNmj
FKTP0e7=9
for(int i=1;;i++) U\plt%2m>
{ 9S`b7U=P
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); m,"tdVo.
//Utility.log(in.readLine()); WUQh[A41
sHeader=httpConnection.getHeaderFieldKey(i); !c' ;L'
if(sHeader!=null) 'wHkE/83
{ <OFqUp*l
if(sHeader.equals("Content-Length")) H s 3*OhK\
{ T[II;[EiE
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); rm;"98~zJ?
break; 2n,73$s
} n]g,)m
} |xC TX
else UjK&`a;V
break; Oc3%pb;
} 9E*K44L/V
} s:.XF|e{
catch(IOException e){e.printStackTrace ();} _\6(4a`,
catch(Exception e){e.printStackTrace ();} VZ!$'??
Z-V%lRQ=b
~&jCz4M
Utility.log(nFileLength); *g}&&$b0
r\D8_S_
U6 R4UK
return nFileLength; NGzqiu"J
} JQ4>S<ttJ
Z*B(L@H
vG}oo
//保存下载信息（文件指针位置） kV<)>Gs
private void write_nPos() _YUF /B'
{ q{(&:~M
try{ bS"M*
output = new DataOutputStream(new FileOutputStream(tmpFile)); jg/<"/E
output.writeInt(nStartPos.length); 0_.hU^fP
for(int i=0;i<nStartPos.length;i++) SHh(ujz,
{ EF~PM
// output.writeLong(nPos); U$Z}<8
output.writeLong(fileSplitterFetch.nStartPos); !X_~|5.
output.writeLong(fileSplitterFetch.nEndPos); tYa*%|!v
} znRhQ+8;!
output.close(); boon=;{p
} ?^Ux+mVE
catch(IOException e){e.printStackTrace ();} ?Ea"%z*c5
catch(Exception e){e.printStackTrace ();} .9QQ]fLs
} K@lV P!z
'& :"/4@)
RkM!BcB
//读取保存的下载信息（文件指针位置） +.cv,1Vx
private void read_nPos() :Aw VeX@
{ (v}:
try{ ]^<~[QK_C
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); S\(_"xJPp
int nCount = input.readInt(); P!EX;+7+x
nStartPos = new long[nCount]; $Plk4 o*g
nEndPos = new long[nCount]; qiN'Tuw9
for(int i=0;i<nStartPos.length;i++) a/fYD2uNo
{ }fZBP]<I(
nStartPos = input.readLong(); e+TNG &_
nEndPos = input.readLong(); Qt 2hb
} f_8~b0`
input.close(); 7(Kc9sJC%%
} F^-4Pyq@
catch(IOException e){e.printStackTrace ();} @dNbL}qQ
catch(Exception e){e.printStackTrace ();} <5%We(3
} htaLOTO;A
J;dFmZOk
;q2T*4NN
private void processErrorCode(int nErrorCode) 6~LpBlb
{ Ok!{2$P8U9
System.err.println("Error Code : " + nErrorCode); &@+;]t
} )3
@T"385>
^da-R;o]
//停止文件下载 (n\ cs$
public void siteStop() %<t/xAge
{ 4y]*"(sQ;
bStop = true; tP-c>|cz
for(int i=0;i<nStartPos.length;i++) =_Rd0,
fileSplitterFetch.splitterStop(); e<K=Q$U.
}{J8U2])k
}: e9\r)
} l<+k[@Vox
} 3Daq5(fLP
//负责部分文件的抓取 xmDwoLU
**FileSplitterFetch.java m`~ Qr~
*/ &0raa
package NetFox; FmPF7
H'2 =yhtVh
Qsa2iw{
import java.io.*; \z 'noc
import java.net.*; yr?\YKV)I
566EMy|
-/X-.#}-
public class FileSplitterFetch extends Thread { 2ip~qZNw><
9}N*(PI
zPe .
String sURL; //File URL UpILr\3U
long nStartPos; //File Snippet Start Position Eh+lLtZ
long nEndPos; //File Snippet End Position vq}V0- <
int nThreadID; //Thread's ID J']W7!p
boolean bDownOver = false; //Downing is over 5> UgBA
boolean bStop = false; //Stop identical gQ~4udla.
FileAccessI fileAccessI = null; //File Access interface DVd/OU
X9R-GT
~$B,K]
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException eR CGr?e4
{ P\JpE
this.sURL = sURL; j*"s~8u4
this.nStartPos = nStart; H UjmJu6f{
this.nEndPos = nEnd; rYl37.QE
nThreadID = id; sdLFBiR
fileAccessI = new FileAccessI(sName,nStartPos);//定位 {<@~;iq
} /.r($Sg^
B}W^s;h
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public void run() _[x(p6Xp
{ 8'y|cF%U
while(nStartPos < nEndPos && !bStop) 8Bhng;jX
{ 4J s>yP
r"+ WUU
kcle|B
try{ ;1KhUf;&F
URL url = new URL(sURL); t%)L8%Jr
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); vzL>ZBeZ
httpConnection.setRequestProperty("User-Agent","NetFox"); kQ +
String sProperty = "bytes="+nStartPos+"-"; ]zO]*d=m
httpConnection.setRequestProperty("RANGE",sProperty); g!$ "CX%8
Utility.log(sProperty); {RK#W~h
rTH@PDk>)
_R]h]<TQ
InputStream input = httpConnection.getInputStream(); bWqGypq4
//logResponseHead(httpConnection); QO8/?^d
[7bY(
+=R:n^r^,
byte[] b = new byte[1024]; ?NL2|8
int nRead; \vI_%su1N
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) |l9AgwDg
{ %UmE=V
nStartPos += fileAccessI.write(b,0,nRead); UJb7v:^
//if(nThreadID == 1) *G9;d0
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); (/%}a`2#o
} QwhPN'U
;BqX=X+#
E$cr3 t7Xy
Utility.log("Thread " + nThreadID + " is over!"); &HWH UWB
bDownOver = true; Y, P-@(
//nPos = fileAccessI.write (b,0,nRead); 7 ir T6O<.
} X@arUs7
catch(Exception e){e.printStackTrace ();} J(Bn n
} '&"7(8E} *
} V#=N?p
T/H*Bo*=5
.m<-)Kx
//打印回应的头信息 \1tce`+
public void logResponseHead(HttpURLConnection con) nP}/#Wy
{ |aZ^K\yIF
for(int i=1;;i++) {Z|C
{ /:S.("Unv
String header=con.getHeaderFieldKey(i); eA!aUu
if(header!=null) w:qwU\U>x
//responseHeaders.put(header,httpConnection.getHeaderField(header)); 2]@U$E='s
Utility.log(header+" : "+con.getHeaderField(header)); z >pq<}R6
else U9JqZ!
break; m_pK'jc
} @FQ@*XD
} ;>PV]0bOm>
-/h$Yb
, 7}Ri
public void splitterStop() ]|-y[iu
{ @gZ%>qe
bStop = true; Y$(G)Fs
} w'UP#vT5&
NWKD:{
4-m}W;igu
} ddw!FH2W (
"dA"N$
&oT]ycz%
/* tvd/Y|bV=
**FileAccess.java )&*&ZL0
*//文件访问(定位，写) Jap v<lV%
package NetFox; 0hPm,H*Y]
import java.io.*; .9`.\v6R
0py0zE6,,
Q 5Ln'La$
public class FileAccessI implements Serializable{ d~.#KS
A0'Yfuie
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 b+{yF
RandomAccessFile oSavedFile; c^m}ep\F5L
long nPos; /ZAEvdO*P
" I:j a7
'06[@Cw
public FileAccessI() throws IOException ,\Cy'TSz
{ 6n>+cX>E
this("",0); kg_TXB
} Z{%h6""
|`,%%p|T%
Zu5`-[mw
public FileAccessI(String sName,long nPos) throws IOException Lw3Z^G
{ 3uN;*f
oSavedFile = new RandomAccessFile(sName,"rw"); P}cGWfj
this.nPos = nPos; d~qDQ6!
oSavedFile.seek(nPos); m,-:(82
} O%rjY
N8:vn0ww
1,Y-_e)
public synchronized int write(byte[] b,int nStart,int nLen) n`}vcVL;
{ c\n\gQ:LQ
int n = -1; `2{x8A
try{ tM~R?9OaJ
oSavedFile.write(b,nStart,nLen); ,*Sj7qb#
n = nLen; y+@7k3"
} =T!M`
catch(IOException e) S?;&vs9j
{ 9^ )=N=wV
e.printStackTrace (); #p0vrQ;5f
} I:[3x2H
zxXm9zrLo
"`16-g97
return n; ]>&au8
} )~rN{W<s`H
&d=j_9
~fEgrF d
} c}lUP(Ss
F?TAyD*
5_{C \S`T
/* @99@do|C
**SiteInfoBean.java ~p^6
*/ *uNa(yd
package NetFox; S$ dFz
Q!MS_ #O
YS%HZFY, "
public class SiteInfoBean { }~yhkt5K
_z~|*7@
A@+pvC&
private String sSiteURL; //Site's URL .XTBy/(0
private String sFilePath; //Saved File's Path 9>%ti&_-jt
private String sFileName; //Saved File's Name GVe[)R
private int nSplitter; //Count of Splited Downloading File BG/M3
j$siCsF
eNpGa0 eG
public SiteInfoBean() Y0 Ta&TYZ0
{//nSplitter的缺省值为5 *e!0ZB3J
//default value of nSplitter is 5 ^ola5wD
this("","","",5); k#&d`?X
} wm!Y5
BH0].-)[y!
YR^J7b\
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) ma,H<0R
{ NvQN
sSiteURL= sURL; 7vubkj&
sFilePath = sPath; K#kU6/
sFileName = sName; |-%[Z
this.nSplitter = nSpiltter; ;i@,TU
+\2{{~_z
N\BB8<F
} ?V3e;n
QJjqtOf>
h%9#~gJ})
public String getSSiteURL() Hcq?7_)
{ l`4hWs\I
return sSiteURL; a"4j9cO
} .k|8nNj
?zM]p"M
xp.~i*!`
public void setSSiteURL(String value) 3{O^q/R
{ {}y"JbXMj
sSiteURL = value; 6=0"3%jn@
} by (xv0v;
,C1}gPQ6<
|>Qj]
public String getSFilePath() 1/:WA:]1,
{ ozy~`$;c
return sFilePath; &A)AV<=>T
} fucG 9B
Q30AaG}f
~7IXJeon
public void setSFilePath(String value) "AMbU68
{ _o`+c wc
sFilePath = value; ?A+-k4l
} yY_Zq\
p"\Z@c
JTA65T{3
public String getSFileName() t2uX+1F
{ ).0klwfV
return sFileName; B+:/!_
} ZF^$?;'3
@8{-B;
jgNdcP
public void setSFileName(String value) 8lk@ev=O&
{ uxLT*,
sFileName = value; +"Flu.+['
} wVX]"o
WdI9))J2S
yyB;'4Af
public int getNSplitter() \"Jgs.
{ "H\1Z,P<m
return nSplitter; %/iD@2r
} ova4
cNOtfn6?F
^h\& l{e
public void setNSplitter(int nCount) ~ "Xcd8:
{ Zawnx=
nSplitter = nCount; nI]8w6eCV
} 0vR gmn
} }@6ws/5
"sh*,K5x|
7vZtEwC)n
/* ZEa31[@B[
**Utility.java @ >_v/U'
*/ p?rh+0wgX
package NetFox; |iSd<
Z$jqB~=^e
In13crr4!
public class Utility { x# MMrV&M
m'HAt~
|z1er"zR)
public Utility() 89n\$7Ff9
{ &Z'3n9zl
ETZE.a
ISa}Km>Q
} =`<9N%
[QUaC3l)
//线程睡眠 r)<c ~\0 7
public static void sleep(int nSecond) gOb"-;Zw
{ M]|tXo$?
try{ 4Ys\<\~d
Thread.sleep(nSecond); (-S\%,hO
} ak1?MKV.
catch(Exception e) |Yb]@9>vn
{ zu/BDyF
e.printStackTrace (); ^Mvgm3hg
} Ln+;HorZ]
} ;Qn)~b~
QrBb!.r
//日志 L;RHshTy
public static void log(String sMsg) uvG'Kx
{ OTe h8h
System.err.println(sMsg); (fNG51h!
} qkXnpv
l(A)Gd5>
<=nOyT9
public static void log(int sMsg) 2o)8'Lp
{ d)>b/0CZ
System.err.println(sMsg); fM/~k>wl
} L0\~K~q
} xqSoE[<v
,F%2'W
S$N!Dj@e;
/* Fv_B(a
**TestMethod.java !}lCwV
*/ )B*D\9\Z
package NetFox; k%D|17I
gUr#3#
h;[<4zw
public class TestMethod { 1u8 k}
g{6FpuA|0
56JxHQu
public TestMethod() 8&Md=ZvK`
{ ///xx/weblogic60b2_win.exe LA]UIM@
try{ i2P:I A|@
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); ;{lb_du2:
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); E]O/'-
SiteFileFetch fileFetch = new SiteFileFetch(bean); k'8tqIUN]
fileFetch.start(); F5y0(=$T
} @#r6->%W
catch(Exception e){e.printStackTrace ();} J5!-<oJ/
y g:&cIr,
#_SsSD=.Sy
} Nn#;Kjul.
<EKTFHJ!
U3**x5F_
public static void main(String[] args) v?Zo5uVoq
{ DuQW?9^232
new TestMethod(); {h*)|J
} -{XDQ{z<%
} ZS<`.L6B3
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