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)); }0>\%C
} vq\L9$WJ
for(int i=0;i<nEndPos.length-1;i++) ?5EMDawt
{ qZlL6
nEndPos = nStartPos[i+1]; L"uidd0(g
} A6xN6{R!
nEndPos[nEndPos.length-1] = nFileLength; tItI^]w2s
} B"`86qc
} @HY P_hR
kkOjAp{<t
;g?o~ev 8
//启动子线程 n<eK\w
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; 6I|9@~!y[
for(int i=0;i<nStartPos.length;i++) cet|k!
{ d_&~^*>
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), Gsy90
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), M=1~BZQ(Z
nStartPos,nEndPos,i); E};1 H
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); l{\k\Q!4
fileSplitterFetch.start(); <!*O[0s
} @mcP-
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), Shss};QZf(
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); ?}S~cgL -
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", ZfS"
nEndPos = " + nFileLength); dO9bxHMnM
// fileSplitterFetch[nPos.length-1].start(); ~F;>4q
sD6vHX%
}kJ9<h,
//等待子线程结束 #9A*BbY
//int count = 0; @-ir
//是否结束while循环 ,fhwDqR ?
boolean breakWhile = false; J6nH|s8
~!e(e2
X1Kze
while(!bStop) awLSY:JI
{ GwG(?_I"
write_nPos(); MEtKFC|p
Utility.sleep(500); ]XWtw21I1
breakWhile = true; Vp8!-[R
jk])S~xl?
ph3dm\U.
for(int i=0;i<nStartPos.length;i++) C2L=i3R
{ JycC\s+%E
if(!fileSplitterFetch.bDownOver) DRRy5+,I
{ #BI6+rfv|
breakWhile = false; R?:(~ X\
break; h0l_9uI
} ei[,ug'
} =[)2DJC
if(breakWhile) <}%gZ:Z6g
break; vfh\X1Ui}
'=UsN_@
n,p \~Tu,
//count++; ^>s{o5H&
//if(count>4) hgdr\ F
// siteStop(); ?~;q r
} LEAU3doK;
LOk J
1R#1Fy%
System.err.println("文件下载结束！"); wy""02j
} zbDK$g6
catch(Exception e){e.printStackTrace ();} p0pA|
} v5L#H=P
TezwcFqH
Xs)?PE[
//获得文件长度 )!sjXiC!h
public long getFileSize() ?!bA#aSbl5
{ qITd.< k
int nFileLength = -1; (>-(~7PR
try{ W"s)s
URL url = new URL(siteInfoBean.getSSiteURL()); J^mm"2
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); oho~?.F
httpConnection.setRequestProperty("User-Agent","NetFox"); Rts}y:44
UJ&gm_M+kL
%vU*4mH
int responseCode=httpConnection.getResponseCode(); x' 3kHw
if(responseCode>=400) %;O# y3,
{ M:%Ll3
processErrorCode(responseCode); XE;aJ'kt
return -2; //-2 represent access is error rTeADu_vf
} 'uLYah
px^brzLQo
Bs<LJzS{V
String sHeader; e!4Kl:
1tH#QZIT
W\z<pP
for(int i=1;;i++) uJJP<mDgA
{ DjiWg(X
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); `^DP<&{
//Utility.log(in.readLine()); bE"J&;|
sHeader=httpConnection.getHeaderFieldKey(i); 5pq9x4&
if(sHeader!=null) '>% c@C[
{ l i2/"~l
if(sHeader.equals("Content-Length")) ,fyqa
{ t=dZM}wj_\
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); Aoy=gK
break; zi,":KDz#
} w6[$vib'
} o q cu<]
else P1"g62R
break; 9~}8?kPNw=
} Q0TKM>
} 6`)Ss5jzk
catch(IOException e){e.printStackTrace ();} NqN9
catch(Exception e){e.printStackTrace ();} 83:qIfF
KI5099_/
OLDEB.@
Utility.log(nFileLength); UG,n q
1i$OcN?x%
TK#-;p_
return nFileLength; T!Uf PfEI
} jHc/ EZB
oX[I4i%G
P/8z
//保存下载信息（文件指针位置） SSr2K
private void write_nPos() '59l.
{ liVDBbS_A?
try{ 3$kElq[
output = new DataOutputStream(new FileOutputStream(tmpFile)); bt?)ryu
output.writeInt(nStartPos.length); ZHc;8|}
for(int i=0;i<nStartPos.length;i++) 7`K)7
{ DZX4c2J
// output.writeLong(nPos); 5$ rV0X,O
output.writeLong(fileSplitterFetch.nStartPos); S3YAc4
output.writeLong(fileSplitterFetch.nEndPos); ZRCUM"R_
} %l)~C%T
output.close(); zuBfkW95+
} Q37zBC0
catch(IOException e){e.printStackTrace ();} i<{/r-w=E
catch(Exception e){e.printStackTrace ();} Z/I`XPmk
} R]_fe4Y0
bqUQadDB
0"=}d y
//读取保存的下载信息（文件指针位置） 3hNb ?
private void read_nPos() ]Oe[;<I
{ ,NQ>,}a0
try{ p2o66t
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); IR*:i{
int nCount = input.readInt(); 3S1`av(tD
nStartPos = new long[nCount]; +4Lj}8,
nEndPos = new long[nCount]; lV2MRxI
for(int i=0;i<nStartPos.length;i++) )1]LoEdm`
{ h3kBNBI )
nStartPos = input.readLong(); ,5Tw5<S
nEndPos = input.readLong(); $a+)v#?,
} x8*@<]!
input.close(); M.}QXta
} .s<tQU
catch(IOException e){e.printStackTrace ();} 74*iF'f?c
catch(Exception e){e.printStackTrace ();} "_/5{Nc$
} hdee]qLS
BGVy \F<
&8 4Izs/[
private void processErrorCode(int nErrorCode) [{9&KjI0K
{ {m<!-B95
System.err.println("Error Code : " + nErrorCode); @GE:<'_:{
} l ~ /y
FI(M 1iJ
}sS1p6z
//停止文件下载 WnC0T5S?U
public void siteStop() f= l*+QY8f
{ U*em)/9
bStop = true; 78<QNlKn
for(int i=0;i<nStartPos.length;i++) &0S/]E`_M
fileSplitterFetch.splitterStop(); `o!a RX
+)K yG
1Du9N[2'P
} b1qli5
} jRIm_)
//负责部分文件的抓取 >@U lhJtW
**FileSplitterFetch.java 4WV)&50
*/ S~ 3|
package NetFox; )Z2t=&Nw
JSm3ZP|GqJ
k~b8=$
import java.io.*; QYTwGThWR
import java.net.*; f^X\N/
pGGx.&5#82
E|Z7art
public class FileSplitterFetch extends Thread { ._z[T@!9
pvJPMx
\ g[A{
String sURL; //File URL 6WnGP>tc.
long nStartPos; //File Snippet Start Position }\/f~?tEh
long nEndPos; //File Snippet End Position yw)Ztg)
int nThreadID; //Thread's ID |1(9_=i'
boolean bDownOver = false; //Downing is over j>OB<4?.+
boolean bStop = false; //Stop identical /I&b5Vp
FileAccessI fileAccessI = null; //File Access interface 8RR6f98FF
;]^JUmxU[d
yLlAK,5P0o
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException +,$"%C
{ mg^\"GC*8
this.sURL = sURL; rfNt
this.nStartPos = nStart; gJ>HFid_C
this.nEndPos = nEnd; k|}S K9
nThreadID = id; "A?_)=zZ
fileAccessI = new FileAccessI(sName,nStartPos);//定位 '%"#]
} <=,KP)
>h m<$3
(&u)FB*
public void run() m=<;)
{ XL7jUi_4:L
while(nStartPos < nEndPos && !bStop) &c!=< <5M
{ @*c) s_
L"6@3
'Kj8X{BSFb
try{ oos35xV.
URL url = new URL(sURL); cIgicp}U
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); $wn"+wX
httpConnection.setRequestProperty("User-Agent","NetFox"); ,FPgbs
String sProperty = "bytes="+nStartPos+"-"; +>5 "fs$Y
httpConnection.setRequestProperty("RANGE",sProperty); \lleO|m
Utility.log(sProperty); TGz5t$]I
?iBHJ{
Aq{m42EAj
InputStream input = httpConnection.getInputStream(); %R{clbbbn
//logResponseHead(httpConnection); -h8!O+7 .
}?Y+GT"E
VmB/X))
byte[] b = new byte[1024]; (IR'~:W
int nRead; k|7XC@i]%
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) P( W8XC
{ o;JBe"1
nStartPos += fileAccessI.write(b,0,nRead); I -obfyije
//if(nThreadID == 1) FBPT@`~v
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); a|\_'#
} -~h2^Oez
.j4IW3)
#|8!0]n'
Utility.log("Thread " + nThreadID + " is over!"); Sk$XC
bDownOver = true; dR_hPBn/@
//nPos = fileAccessI.write (b,0,nRead); w`VmN}pR
} .n`MPx'
catch(Exception e){e.printStackTrace ();} k>Qr14F
} pDlh^?cux
} V@K}'f~
x9HA^Rj4-
&w3LMOT
//打印回应的头信息 8X]j;Rb
public void logResponseHead(HttpURLConnection con) ~4*9w3t
{ q6{%vd
for(int i=1;;i++) )x"Z$jIs
{ H2RNekck
String header=con.getHeaderFieldKey(i); /kVy#sT|
if(header!=null) ?lU]J]
//responseHeaders.put(header,httpConnection.getHeaderField(header)); y\@;s?QL
Utility.log(header+" : "+con.getHeaderField(header)); ASaG }h
else !U/:!e`N
break; ][bz5aV
} _ #l b\
} );;UNO21+
eeb8v:4
# dxlU/*
public void splitterStop() g m],
{ s:cS 9A8
bStop = true; 0tB9X9:,
} sa+:c{
ld[]f*RuW
,^o^@SI)
} p9_45u`u2
ASy7")5
b)w3 G%Xx
/* k=bv!T_o
**FileAccess.java n*iaNaU"'
*//文件访问(定位，写) M7,|+W/RK
package NetFox; sS(^7GARa
import java.io.*; =GM!M@~,Ab
YQX>)'
? *I9
public class FileAccessI implements Serializable{ W.:kE|a.g
rT}d<cSf
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 o`j%$K4?5
RandomAccessFile oSavedFile; J(/ eR,ak
long nPos; oRWsi/Zf
:@b>,{*4zS
)vGRfFjw_
public FileAccessI() throws IOException GJy,)EO6{
{ b<.+WkO
this("",0); 'Dk(jpYB
} !b _<_Y{l
s[s6E`Q
zLXtj-
public FileAccessI(String sName,long nPos) throws IOException 9y]$c1
{ !8=uBS%
oSavedFile = new RandomAccessFile(sName,"rw"); x|<|eRYK
this.nPos = nPos; &|E2L1
oSavedFile.seek(nPos); {/0,lic
} vW)GUAF[
p6}jCGJ
*%)L?*
public synchronized int write(byte[] b,int nStart,int nLen) vlj|[joXw
{ NKd@Kp`,
int n = -1; 7 cIVK}&
try{ )s=z i"
oSavedFile.write(b,nStart,nLen); tfv]AC7x
n = nLen; Tu/JhP/g,`
} l3iL.?&Pa
catch(IOException e) 053W2Si
{ H#Og0gEE}5
e.printStackTrace (); V">Uh@[J_
} `XWxC:j3%
eIqj7UY_
DD3J2J
return n; w@%W{aUC
} KP<J~+_ik
@Qc['V)
qo. 6T
} p-(Z[G*
Fsq S)
7L-%5:1%
/* x6)
**SiteInfoBean.java RXWjFv~/
*/ e&0B4wVAQ
package NetFox; zw5~|<
WX\%FJ
;D^)^~7dh
public class SiteInfoBean { 'Ux_X:,:;
|y:DLsom?i
J<`RlDI
private String sSiteURL; //Site's URL Dh9-~}sW'
private String sFilePath; //Saved File's Path wyc,Ir
private String sFileName; //Saved File's Name ~AE034_N
private int nSplitter; //Count of Splited Downloading File yh0|f94m
%*19S.=l
\W(p)M
public SiteInfoBean() pKH4?F
{//nSplitter的缺省值为5 \ qs6%
//default value of nSplitter is 5 W#lvH=y
this("","","",5); hr{%'DAS
} -91l"sI
y2qESAZ%k}
l.34h
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) .e"jnP~
{ U|Jo[4A
sSiteURL= sURL; 6/-!oo
sFilePath = sPath; zEhy0LLm
sFileName = sName; #VO2O0GR
this.nSplitter = nSpiltter; :,ym)|YV
~<Lf@yu-{
?\O+#U%W
} 9=kTTFs
bL&]3n9Rwu
)Xh_q3=
public String getSSiteURL() 5PPy+36<~
{ eY(usK
return sSiteURL; -pD&@Wlwak
} `?D_=Gw
V!opnLatYS
-DuiK:mp
public void setSSiteURL(String value) KqSa"76R
{ P5d@-l%}
sSiteURL = value; :O!G{./(_
} nEp'l.T
|,7J!7T(I
@LE?XlhD
public String getSFilePath() LQh\j|e9
{ Fd\XDc[g
return sFilePath; V?O%kd
} o6y,M!p@
y(]|jRo
dH/t|.%
public void setSFilePath(String value) b #^aM
{ 1`}fbX;"m)
sFilePath = value; )4`Ml*7x
} QhG-1P3#
Gzir>'d2'V
bMUIe\/v[
public String getSFileName() vV[dJ%
{ $HXB !$d
return sFileName; 0%qUTGj
} &S3W/lQs
|O)deiJRy
%'t~e?d!
public void setSFileName(String value) uv-W/p
{ R|CY4G j
sFileName = value; d=#p w*w
} f~q&.,I(
KJ)nGoP>
_ <;Q=?'*
public int getNSplitter() {.lF~cOu
{ ft'iv
return nSplitter; ,SyUr/D
} !U#++Zig%
x7@WWFF>
r~}}o o4K
public void setNSplitter(int nCount) &CL|q+-
{ ZM vTDH!
nSplitter = nCount; 6|KX8\,A@
} TN %"RL
} bSr 'ji
r9M={jC
Z M+Hb_6f
/* 0`!Q-G7
**Utility.java baNfS
*/ i)2))C
package NetFox; Ft7a\vn*B
N-rmk
)RYnRC#O
public class Utility { H{f_:z{{
2ZO'X9
H<;Fb;b
public Utility() *!'&:
{ 5|R2cc|"9
q`aY.dD=O
y@M}T{,/
} 3\KII9
BJ9sR.yX62
//线程睡眠 h6h1.lZ
public static void sleep(int nSecond) u3wC}Zo
{ ;-?ZI$
try{ {}pqxouE
Thread.sleep(nSecond); Is@a,k
} '%EZoc/U
catch(Exception e) pIu H*4Vz
{ uit-Q5@~
e.printStackTrace (); w`}9/s;$
} s1vrzze
} Z) Xs;7
M_1Tx
//日志 e_=pspnZ
public static void log(String sMsg) Z02s(y=k1
{ 16QbB;
System.err.println(sMsg); z`/.v&<>V
} #Q3PzDfj
RW7oL:$dt
%?f:"
public static void log(int sMsg) $a^isd4
{ qd+[ShrhqZ
System.err.println(sMsg); }IN_5o((
} {TncqA
} c,q"}nE8w
%%~}Lw
4$aO;Z_
/* z@~&Kwf\}
**TestMethod.java >C3NtGvy
*/ Y_@"v#,
package NetFox; A$~xG(
=u8D!AxT
fT3*>^Uv
public class TestMethod { v'Vt .m&9&
#\;>8
9>Uq$B
public TestMethod() ^ L^F=qx
{ ///xx/weblogic60b2_win.exe Ao":9r[V
try{ )M'UASB;8
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); ~"0@u
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); yIIETE
SiteFileFetch fileFetch = new SiteFileFetch(bean); oM<!I0"gC+
fileFetch.start(); A*;?U2
} _E6}XNS
catch(Exception e){e.printStackTrace ();} o}=.
?Hi}nsw
sc8DY!|OYN
} CofH}-
`x} Dk<HF
3}4p_}f/[4
public static void main(String[] args) zq;DIWPIoJ
{ &G/|lv>j
new TestMethod(); u<]mv
} XocsSs
} f>r3$WKj
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