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)); UD-+BUV
} |{#St-!-7
for(int i=0;i<nEndPos.length-1;i++) Ok!P~2J
{ L]=]/>jQ6
nEndPos = nStartPos[i+1]; YK/? mj1x
} ?w:\0j5~
nEndPos[nEndPos.length-1] = nFileLength; k4']q
} i]ZGq7YJ%
} U1YqyG8
pr<u 5
7h\is
//启动子线程 "Hw%@]#
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; Y2L{oQ.C2
for(int i=0;i<nStartPos.length;i++) NfoHQU<n
{ MSCH6R"5
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), \l/(L5gY
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), d:'{h"M6
nStartPos,nEndPos,i); *$A`+D9
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); hkPMu@BI
fileSplitterFetch.start(); hi(b\ABx
} 5iw\F!op:
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), #(tdJ<HvC|
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); z4YDngf=4
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", N3u06
nEndPos = " + nFileLength); /dCsZA
// fileSplitterFetch[nPos.length-1].start(); ~cm4e>o
$n<1D -0!r
-b!?9T?}
//等待子线程结束 RvR.t"8
//int count = 0; #N][-i
//是否结束while循环 #6M |T+=
boolean breakWhile = false; ^&;,n.X5Z
K@p9_K8
^]o H}lwO
while(!bStop) n/v.U,f&l@
{ cxR.:LD}
write_nPos(); .rBU"Rbo
Utility.sleep(500); KpGx<+0p
breakWhile = true; ;-3&yQ7N)
X5o*8Bg4M
q7CLxv &QG
for(int i=0;i<nStartPos.length;i++) pLu5x<
{ aVR!~hvFs
if(!fileSplitterFetch.bDownOver) "~VKUvDu
{ T={!/y+
breakWhile = false; k~)CJ6}
break; !60U^\
} >~,~X9
} X@kgc&`0
if(breakWhile) 1tY+0R
break; Tf#Op v)
./I?|ih
u0W6u} 4;
//count++; eBa#Z1Z
//if(count>4) )xVf3l pQ
// siteStop(); lW"0fZ_x'E
} ~C{:G;Iy0
VP!4Nob
,#XXwm ^I
System.err.println("文件下载结束！"); f}yRTR GJv
} @G;9eh0$
catch(Exception e){e.printStackTrace ();} ZY<RNwu
} jTS8 qu
k;cIEEdZD
iY>P7Uvvz
//获得文件长度 >)D=PvGlmp
public long getFileSize() ?$`kT..j,u
{ \dQc!)&C9
int nFileLength = -1; Yz;7g8HI
try{ 3D6&0xTq
URL url = new URL(siteInfoBean.getSSiteURL()); 53hX%{3
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); &B5&:ib1D
httpConnection.setRequestProperty("User-Agent","NetFox"); `a52{Wa
R?1Z[N
v{$?Ow T/u
int responseCode=httpConnection.getResponseCode(); TFOx=_.%i
if(responseCode>=400) a=W%x{
{ '`;=d<'
processErrorCode(responseCode); Z'A 3\f
return -2; //-2 represent access is error qMEd R;o
} 0to`=;JI
u"zR_CzYc
%KVmpWku
String sHeader; ]-t>F
xbi\KT`~
1>[#./@
for(int i=1;;i++) RL&0?OT
{ mxEe -q
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); .<vXj QE
//Utility.log(in.readLine()); _#Hd2h
sHeader=httpConnection.getHeaderFieldKey(i); >NPK;Vu
if(sHeader!=null) .,6o):
{ HT/!+#W.
if(sHeader.equals("Content-Length")) ,8zJD&HMx
{ i%!<9D~n
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); [PN2^
break; 6&]Z'nW0k
} eV%{XR?y
} auGK2i
else BEax[=&W
break; \s[L=^!
} r<kgYU`
} *A`ZcO=
catch(IOException e){e.printStackTrace ();} UU(Pg{DA6
catch(Exception e){e.printStackTrace ();} db_Qt'>
}Tk:?U{
:YRHO|
Utility.log(nFileLength); NL:dyV}
&*o4~6pQ#
,FP0n
return nFileLength; ` Ft-1eE
} b5MU$}:
N?t*4Y
pq]z%\$u
//保存下载信息（文件指针位置） W\-`}{B_/
private void write_nPos() ]gX8z#*k
{ 3~R,)fO;
try{ /$clk=
output = new DataOutputStream(new FileOutputStream(tmpFile)); :' 5J[]J
output.writeInt(nStartPos.length); J0vQqTaT
for(int i=0;i<nStartPos.length;i++) P(yLRc
{ Wgs6}1bg
// output.writeLong(nPos); sMAj?]hI$
output.writeLong(fileSplitterFetch.nStartPos); Q7e4MKy7
output.writeLong(fileSplitterFetch.nEndPos); LK4NNZf7
} ">!pos`<C
output.close(); uO]|YF
} vn*K\,
catch(IOException e){e.printStackTrace ();} J|hVD
catch(Exception e){e.printStackTrace ();} `3jwjy|5
} wZ0bD&B
YJ6:O{AL1
wEq&O|Vj
//读取保存的下载信息（文件指针位置） #5h_{q4l
private void read_nPos() L8n?F#q
{ @r[SqGa:
try{ mW{uChHP
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); $,O8SW.O$
int nCount = input.readInt(); &\ca ? #
nStartPos = new long[nCount]; Z,AY<[/C
nEndPos = new long[nCount]; lO|LvJyx
for(int i=0;i<nStartPos.length;i++) y+Nw>\|S
{ Q}^Ip7T
nStartPos = input.readLong(); 1p5'.~J+Q
nEndPos = input.readLong(); \:F$7 *Ne
} &HLG<ISw
input.close(); D1+1j:m
} c2Z!Vtd
catch(IOException e){e.printStackTrace ();} F,)+9/S&
catch(Exception e){e.printStackTrace ();} [z\baL|
} &,8Qe;
117lhx].'
UrciCOQf
private void processErrorCode(int nErrorCode) Bx\ o8k
{ ugXDnM[S%
System.err.println("Error Code : " + nErrorCode); OcWKK!A
} \:s%;s51
0\"#Xa+}8
<uBRLe`)
//停止文件下载 huA?*fat
public void siteStop() x6JV@wA&
{ A@_>9;
bStop = true; ~9APc{"A
for(int i=0;i<nStartPos.length;i++) jP/Vqe%%8
fileSplitterFetch.splitterStop(); ;=IJHk1&
5m'AT]5Tn_
d3\?:}o,
} %^E7Iqc
} _(?`eWo
//负责部分文件的抓取 Z5oDj|&l}
**FileSplitterFetch.java _#v"sGmN
*/ l]D$QT3
package NetFox; 'bLP#TAzf
j&/+/s9N
lijTL-3
import java.io.*; (Nz`w
import java.net.*; *k#"@
[*It' J^
z.SKawm6T
public class FileSplitterFetch extends Thread { *-fd$l.
ha;fxM]
4x-,l1NMR
String sURL; //File URL GPGPteC
long nStartPos; //File Snippet Start Position e<{d{
long nEndPos; //File Snippet End Position V,VL?J\
int nThreadID; //Thread's ID 9XQE5^
boolean bDownOver = false; //Downing is over bJ 6ivz
boolean bStop = false; //Stop identical 6&'kN2
FileAccessI fileAccessI = null; //File Access interface P-[})Z=
JW><&hY$"
XZ8rM4 ]
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException U!Zj%H1XQ0
{ B*}]'
this.sURL = sURL; `WCL-OoZc5
this.nStartPos = nStart; H;_Ce'oU(
this.nEndPos = nEnd; 6W1+@ q
nThreadID = id; 12L`Gi
fileAccessI = new FileAccessI(sName,nStartPos);//定位 z]hRc8g}d
} {E(2.'d
#r"|%nOfY
( sl{Rgxe*
public void run() u/|@iWK:
{ !hfpa_5
while(nStartPos < nEndPos && !bStop) NBasf n
{ :+>7m
;*zLf 9i
Hc<@T_h+2
try{ 8Uh|V&
URL url = new URL(sURL); 6Hb a@Q1`
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); z__t8yc3
httpConnection.setRequestProperty("User-Agent","NetFox"); -Wmb M]Z
String sProperty = "bytes="+nStartPos+"-"; a%HNz_ro
httpConnection.setRequestProperty("RANGE",sProperty); vOCaru?~h
Utility.log(sProperty); S]%,g%6i
R!/JZ@au<
4P)#\$d:
InputStream input = httpConnection.getInputStream(); hTO2+F*
//logResponseHead(httpConnection); *re?V9
j3%Wrt
A)!W VT&2A
byte[] b = new byte[1024]; RAhDSDf
int nRead; V D7^wd9
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) i Pr(X
{ VfJ{);
nStartPos += fileAccessI.write(b,0,nRead); ,0AS&xs$
//if(nThreadID == 1) [S]q'c)
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 3 ;F
} F[O147&C
,)d`_AD+5
";&PtLe
Utility.log("Thread " + nThreadID + " is over!"); YwY?tOxBe
bDownOver = true; 0e#PN@
//nPos = fileAccessI.write (b,0,nRead); Z/:yYSq
} E Lq1
catch(Exception e){e.printStackTrace ();} ;c]O*\/
} 6W3oIt
} ]Oo!>iTQi
:epB:r
p`7d9MV^
//打印回应的头信息 0&|M/
public void logResponseHead(HttpURLConnection con) [R8BcO(
{ r9bAbE bI
for(int i=1;;i++) C_ d|2C6
{ W[`ybGR<
String header=con.getHeaderFieldKey(i); (>u1O V
if(header!=null) ND?"1/s
//responseHeaders.put(header,httpConnection.getHeaderField(header)); E]&N'+T
Utility.log(header+" : "+con.getHeaderField(header)); C^'r>0
else /<[_V/g[t?
break; ZHeue_~x4
} dn])6Xl;i
} 0Qeda@J
S?i^ ~
O\o@]
public void splitterStop() x4g6Qze
{ yyu-y0_
bStop = true; cf>lY
} By!u*vSev
FVP,$
+&f_k@+
} ,Iz9!i J"
Yyd}>+|<,
!~F oy F
/* S{2;PaK
**FileAccess.java 8'3&z-
*//文件访问(定位，写) =z9,=rR4
package NetFox; [X@{xF^vBQ
import java.io.*; }0H<G0
S3U]AH)C
@%u}|iF|
public class FileAccessI implements Serializable{ ?uTuO
ph(LsPT-
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 q0>9T
RandomAccessFile oSavedFile; `l?MmIJ
long nPos; |8k^jq
F:<+}{Av
>#mKM%T2MJ
public FileAccessI() throws IOException RYC%;h
{ Ym]g0a
this("",0); &e).l<B
} buzpmRoN)
W"#<r
RB""(<
public FileAccessI(String sName,long nPos) throws IOException <T.R%Jys
{ <)O#Y76s
oSavedFile = new RandomAccessFile(sName,"rw"); q\!"FDOl4
this.nPos = nPos; n@bkZ/G
oSavedFile.seek(nPos); +J|LfXgB
} 5"U5^6:T
/M]P&Zb |
{*CG&-k2D
public synchronized int write(byte[] b,int nStart,int nLen) BBX/&d8n
{ suhnA(T{
int n = -1; .':17 $c`H
try{ c"`HKfL
oSavedFile.write(b,nStart,nLen); RmKbnS$*q
n = nLen; Z9% u,Cb
} Pk5\v0vkg
catch(IOException e) >yVrIko
{ ^56D)A=
e.printStackTrace (); 3#udzC
} d1^5r 31
^"/TWl>jB
*CF80DJ
return n; ;VCFDE{K=
} F [-D +Nka
O7Jp;
=r`E%P:
} AoxORPp'
4TU\SP8sM
?_S);
/* {ByKTx&
**SiteInfoBean.java #|:q"l9
*/ #X!seQ7a
package NetFox; *}(B"FSO
r_'];
1T~`$zS7
public class SiteInfoBean { 4^Ks!S>K{8
BUh(pS:
1,Pg^Xu
private String sSiteURL; //Site's URL "GqasbX
private String sFilePath; //Saved File's Path *E|3Vy{4
private String sFileName; //Saved File's Name l!j=em@
private int nSplitter; //Count of Splited Downloading File 7X$pgNRx/a
DBvozTsF~
ep48 r>
public SiteInfoBean() |z}VP-L
{//nSplitter的缺省值为5 8rU| Oh
//default value of nSplitter is 5 2Z^p)
this("","","",5); Gh{9nM_\"
} ?5pZp~
KV{
#f=41d%
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) 0!:%Ge_
{ 9dp4&&Z+F
sSiteURL= sURL; 2ss*&BR.
sFilePath = sPath; ` -f\6r|:)
sFileName = sName; vf?m6CMU!
this.nSplitter = nSpiltter; Jl6biJx
11fV|b%
mv*M2NuhT
} Ve"M8-{oKk
=7~;*Ts
#.}&6ZP
public String getSSiteURL() *a(GG
{ [Q8vS;.
return sSiteURL; <1~_nt~(*
} [*ug:PG
K7qR
6k37RpgH
public void setSSiteURL(String value) Y|-&=
{ {ueDwnZ
sSiteURL = value; rXGaav9
} ldaT: er9
J}@.f-W\j
VjiwW%UOM
public String getSFilePath() ?%Pi#%P
{ XzBl }4s
return sFilePath; 56Lt "Z F
} RtaMrG=D
\:Hh'-77q
3Z}m5f`t
public void setSFilePath(String value) mI;\ UOh'
{ NeewV=[%
sFilePath = value; (I1^nrDP.
} H,!yG5yF
K1-3!G
sa"!ckh
public String getSFileName() Ob|tA
{ xCu\jc)2
return sFileName; ~!Rf5QA85
} b|.<rV'BTt
B-$ps=G+z
/5f=a
public void setSFileName(String value) cdL0<J b,
{ |Yi_|']#
sFileName = value; &c= 3BEh
} "t>H B6^
+5Y;JL<%/
>+[{m<Eq
public int getNSplitter() ge{%B~x
{ $cO-+Mr-~
return nSplitter; j W-K
} clT[?8*
'L%)B-,n
[hiV#
public void setNSplitter(int nCount) - l0X]&Ex
{ <Um5w1
nSplitter = nCount; cw~-%%/
} Ige*tOv2
} dhr-tw
llpgi,-=
r)dXcus
/* zwlz zqV
**Utility.java *W4~.peoE
*/ o<Rrr,
package NetFox; XE:bYzH
xZMAX}8v
)EsFy6K:
public class Utility { _E^ !,Wz
*Y ?&N2@c
,Mn?h\
public Utility() 2cv=7!K4Uv
{ )aX#RM? N
~/Kqkhq+c
*nY$YwHB
} S^SF!k=
`{nzw$
//线程睡眠 :1!k*5
public static void sleep(int nSecond) Rdy-6
{ B,{Q[
try{ [g lhru=+
Thread.sleep(nSecond); 3=^B &AB
} v*@R U
catch(Exception e) 6"o@d8>v
{ )!l1
e.printStackTrace (); iuoZk5O
} -$f$z(h
} G>+iisb%
11-?M
//日志 !4+@b s
public static void log(String sMsg) w`>g^_xsg
{ S\A9r!2
System.err.println(sMsg); JjBlje
} =K6{AmG$
YM +4:P2
D^H4]7wG@
public static void log(int sMsg) SrvC34<7
{ ia%U;M
System.err.println(sMsg); n'<F'1SWv
} b5UIX Kim
} g;</|Z
pIvr*UzY
I oC}0C7
/* _I#a`G
**TestMethod.java yJHFo[wGMJ
*/ (!diPwcv
package NetFox; D~f[Rg
(fC U+
h_xzqElZu
public class TestMethod { FmtV[C#
5[rA>g~
M}!E :bv'
public TestMethod() S>EO6z#
{ ///xx/weblogic60b2_win.exe 0d #jiG
try{ 0/b3]{skK
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); _n!W4zwi
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); jsIT{a*]
SiteFileFetch fileFetch = new SiteFileFetch(bean); 1(m[L=H5>
fileFetch.start(); NvjKB)J
} .^!uazPE0
catch(Exception e){e.printStackTrace ();} ]*yUb-xY
j{H,{x
u~j&g
} aumM\rY
N5@l[F7I
ey) 8q.5
public static void main(String[] args) $ud\CU:r
{ (p}N cn.
new TestMethod(); N/eFwv.Er
} z%[^-l-
} 5^GrG|~
点击下载更多相关资料