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)); 1vd+p!n
} 7NqV*
for(int i=0;i<nEndPos.length-1;i++) tqf-,BLh
{ =#fvdj
nEndPos = nStartPos[i+1]; tR/ JY;jn
} TI&J>/z;$
nEndPos[nEndPos.length-1] = nFileLength; e%>E| 9*u
} rt;>pQ9,
} 0zNS;wvv&
4Lb<#e13R?
U]3JCZ{]0E
//启动子线程 u8=|{)yL
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; (o=iX,@'2
for(int i=0;i<nStartPos.length;i++) Q{kuB+s
{ Nh-*Gt?
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), Vi-@z;k
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), |@|D''u>6
nStartPos,nEndPos,i); 4B pm{b
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); qm_E/B
fileSplitterFetch.start(); <O&s 'A[
} T^SOq:m&
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), M#|xj <p
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); _<Tz1>j=
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", Rznr9L
nEndPos = " + nFileLength); vM8]fSc
// fileSplitterFetch[nPos.length-1].start(); 5?"ZM'4
|u=57II#xK
XA%?35v~
//等待子线程结束 !4fL|0
//int count = 0; M-t9zT
//是否结束while循环 D1a2|^zt
boolean breakWhile = false; eU*hqy?0
Y?x3JU0_
k0|InP7
while(!bStop) ^2tCDm5
{ ]~,'[gWb
write_nPos(); ;[ojwcK[ZF
Utility.sleep(500); d1TG[i<J_
breakWhile = true; (Zkt2[E`
?y kIi/
}wKU=Vm
for(int i=0;i<nStartPos.length;i++) kY&j~R[C
{ :l{-UkbB
if(!fileSplitterFetch.bDownOver) 5j%jhby?
{ E2cmT$6
breakWhile = false; LdV_7)
break; <jjaqDSmz
} K;O\Pd
} y6\#{
if(breakWhile) qr1^i1%\
break; V#Eq74ic
aqgSr|
[;+YO)
//count++; EY(4<;)
//if(count>4) NKN!X/P
// siteStop(); {fs(+ 0ei
} eP8wTStC
&40dJ~SQ
|/Z4lcI
System.err.println("文件下载结束！"); 6|x<)Gc
} PT=%]o]
catch(Exception e){e.printStackTrace ();} NO)*UZ
} ~-x\E#(
$@X,J2&
,;;~dfHm
//获得文件长度 &kGSxYDk%
public long getFileSize() XCY4[2*a>
{ I;LqyzM
int nFileLength = -1; H>?@nYP
try{ 5sRNqTIr
URL url = new URL(siteInfoBean.getSSiteURL()); L;;x%>
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); &0myA_So
httpConnection.setRequestProperty("User-Agent","NetFox"); [aW#7
-!"8j"pA:
B Xp3u|t
int responseCode=httpConnection.getResponseCode(); J2-xnUa]7
if(responseCode>=400) 6AY%onY
{ L'(^[vR(
processErrorCode(responseCode); 9dAsXEWh
return -2; //-2 represent access is error mjpH)6aD0
} ?Z"}RMM)8
wlJ_,wA
1Y_fX
String sHeader; 2q>4nN
dpS
%"tf`,d~3
for(int i=1;;i++) gxiJ`.D=
{ 2]l*{l^ Bl
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); v%r!}s
//Utility.log(in.readLine()); f/xBR"'
sHeader=httpConnection.getHeaderFieldKey(i); IdM;N
if(sHeader!=null) \%(R~H
{ S<44{ oH
if(sHeader.equals("Content-Length")) x<"e
{ vv3?ewr y
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); $kdfY'u
break; FM5$83Q
} Nz8iU@!a
} [(1O_X(M
else =0A{z#6
break; M&L"yQA
} |2Dlw]d
} "+Kr1nW
catch(IOException e){e.printStackTrace ();} &b%6pVj
catch(Exception e){e.printStackTrace ();} ,b/0_Q
>2ct1_
5:6mptn>
Utility.log(nFileLength); QP'* )gjO7
(NP=5lLH
GIp?}tM
return nFileLength; n D?XP<9UU
} hd900LA}
p"ZPv~("V
d7@ N~<n
//保存下载信息（文件指针位置） PO#FtG
private void write_nPos() D:f#
{ HHdc[pJ0D
try{ kG E|17I
output = new DataOutputStream(new FileOutputStream(tmpFile)); h<uQ~CQg
output.writeInt(nStartPos.length); R!`#pklB
for(int i=0;i<nStartPos.length;i++) UV=TU=A\o
{ ls=<c<
// output.writeLong(nPos); 1i{B47|
output.writeLong(fileSplitterFetch.nStartPos); &]5<^?3
output.writeLong(fileSplitterFetch.nEndPos); Zhw _L
} d(&vIjy
output.close(); T]+*}C
} Z]aSo07
catch(IOException e){e.printStackTrace ();} YWTo]DJV
catch(Exception e){e.printStackTrace ();} McfSB(59
} m<j ^cU#J
\.{?TB
zMDR1/|D
//读取保存的下载信息（文件指针位置） .UJk0%1
private void read_nPos() "5@Y\L
{ wM><DrQ
try{ =w8*n2
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); >k:)'*
int nCount = input.readInt(); ,5q^/h
nStartPos = new long[nCount]; t ;[Me0
nEndPos = new long[nCount]; RD~QNj9,T
for(int i=0;i<nStartPos.length;i++) z*FlZLHY
{ Ih{~?(V$
nStartPos = input.readLong(); T_r[#j
nEndPos = input.readLong(); *rWE.4=&
} ?Hy++
input.close(); B]jh$@
} r+>9O
catch(IOException e){e.printStackTrace ();} 1~j.jv$
catch(Exception e){e.printStackTrace ();} c$p1Sovw
} thOCzGJ$
p@P[pzxI
X,~8) W
private void processErrorCode(int nErrorCode) 4}gwMjU-B
{ GU!|J71z
System.err.println("Error Code : " + nErrorCode); am`eist:
} J9/w_,,R$
"5{\0CfS
4((Z8@iX/
//停止文件下载 E_$ST3
public void siteStop() BWd?a6nU}
{ ;DGp7f#9
bStop = true; <F&S
for(int i=0;i<nStartPos.length;i++) a"~W1|JC"
fileSplitterFetch.splitterStop(); rq$%
$UKDXQF"
e&E*$G@.7
} qWo|LpxWt
} DD;PmIW
//负责部分文件的抓取 "|f;
**FileSplitterFetch.java m|p}Jf!
*/ A=BpB}b
package NetFox; T%Z`:mf
~]N% {;F}
2-2'c?%
import java.io.*; ? [=P
import java.net.*; yp8 .\.
cLamqZf3
MECR0S9
public class FileSplitterFetch extends Thread { aX0sy\Z]j
^E>}A
enZW2o97c
String sURL; //File URL h4sEH
long nStartPos; //File Snippet Start Position XxV]U{i!
long nEndPos; //File Snippet End Position qbB.Z#w
int nThreadID; //Thread's ID >GqIpfn
boolean bDownOver = false; //Downing is over GJ!usv u
boolean bStop = false; //Stop identical x<imMJ
FileAccessI fileAccessI = null; //File Access interface d+=;sJ
i^j{l_-JE
W&GDE
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException 594$X@!v
{ \,~gA
this.sURL = sURL; 0\u_\%[
this.nStartPos = nStart; ; <3w ,r
this.nEndPos = nEnd; <;M6s~
nThreadID = id; p_tMl%K
fileAccessI = new FileAccessI(sName,nStartPos);//定位 P^+Og_$
} *,mbZE=<
\}Hk`n)Aq
b@nbXm]Z
public void run() H,] D}r
{ ;b(/PH!O
while(nStartPos < nEndPos && !bStop) Zuwd(q
{ BC&Et62*
=w,%W^"E
^1}}-9q
try{ hX_;gR&R
URL url = new URL(sURL); D4_D{\xhO
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); +BmA4/P$
httpConnection.setRequestProperty("User-Agent","NetFox"); df}B:?Ew.
String sProperty = "bytes="+nStartPos+"-"; 4ajBMgD]KG
httpConnection.setRequestProperty("RANGE",sProperty); -j<m0XUQ
Utility.log(sProperty); m_oBV|v{
852$Ui|I
y=-d*E
InputStream input = httpConnection.getInputStream(); ZO:{9vt=/
//logResponseHead(httpConnection); >pz/wTOi
-K+grsb g
J>x)J}:;
byte[] b = new byte[1024]; R0{+Xd
int nRead; IC7n;n9
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) :x= ZvAvo
{ r0?`t!%V
nStartPos += fileAccessI.write(b,0,nRead); Xo}w$q5
//if(nThreadID == 1) ,8@@r7
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); B-JgXW.\0
} CfA F.H
S =eP/
wXfy,W
Utility.log("Thread " + nThreadID + " is over!"); >(*jL
bDownOver = true; <Eq^rh
//nPos = fileAccessI.write (b,0,nRead); rXvvJIbi
} l0Y(9(M@
catch(Exception e){e.printStackTrace ();} foaNB=,
} (iH5F9WO
} ^h=;]vxO
65qH
v='7.A
//打印回应的头信息 eRC@b^~
public void logResponseHead(HttpURLConnection con) Z3"f7l6
{ Ix-FJF-
for(int i=1;;i++) {U7j
{ X2Y-TET
String header=con.getHeaderFieldKey(i); amgYr$)m
if(header!=null) ^i#F+Q`1
//responseHeaders.put(header,httpConnection.getHeaderField(header)); QfRt3\^`
Utility.log(header+" : "+con.getHeaderField(header)); mLKwk6I
else )";g*4R[
break; j =[Td
} g7#_a6
} ,!PNfJA2
dLG5yx\js
%]RzC`NZ
public void splitterStop() rQ.j$U
{ O zY&^:>
bStop = true; ytr~} M%
} <dh7*M
!)KX?i[Q
2A {k>TjQ
} Z6 (;~"Em
(T!Q
e>y"V;Mj
/* bZ:w_z[3=
**FileAccess.java ZN',=&;n'
*//文件访问(定位，写) 5H`k$[3V
package NetFox; ?ZE1>L7e
import java.io.*; m>:3Ku
(H0nO7Bk
WZ;f3 "
public class FileAccessI implements Serializable{ .u)Po;e`
pgfI1`h
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 Q_qc_IcM y
RandomAccessFile oSavedFile; mp%i(Y"vp
long nPos; o1-Zh!*a*
<JDkvpckx.
Z3T:R"l;
public FileAccessI() throws IOException OV Iu&6#
{ p7Gs
this("",0); 5(tOQ%AQ
} IgQW 5E#
Z_cTuu0'
m?>$!B4jFB
public FileAccessI(String sName,long nPos) throws IOException ES<"YF
{ bY&s$Ry3"
oSavedFile = new RandomAccessFile(sName,"rw"); #*1\h=bzmW
this.nPos = nPos; 3QZw
oSavedFile.seek(nPos); q?e97a
} E;9SsA
7YkxIzE
b:WlB[5
public synchronized int write(byte[] b,int nStart,int nLen) rW&8#&
{ >& \QLo[5
int n = -1; G}AfCd4
try{ ^+Ec}+ Q
oSavedFile.write(b,nStart,nLen); e(,sFhR
n = nLen; r8}GiP0|
} RWz^ MV5K
catch(IOException e) *GTCVxu
{ v.c2(w/P
e.printStackTrace (); }q)oLC
} %7z
J}nE,U2
uJ{N?
return n; V2V^*9(wu@
} XW%!#S&;X
Cj31'
Y_xPr%%A
} GadQ \>
4-lEo{IIM
d {T3
/* 3QL'uk
**SiteInfoBean.java PGOi#x
*/ )CSb\
package NetFox; Lg sQz(-
}pTy mAN
e{>X2UNW
public class SiteInfoBean { Wx;:_F7'\
Yq $(Ex
5NZob<<
private String sSiteURL; //Site's URL Wm7Dy7#l
private String sFilePath; //Saved File's Path &w- QMjM>
private String sFileName; //Saved File's Name uF+if`?
private int nSplitter; //Count of Splited Downloading File )?:V5UO\
dl6d!Nz*
1ZOHyO
public SiteInfoBean() |l 03,dOF
{//nSplitter的缺省值为5 Q+U}
//default value of nSplitter is 5 %mAgE\y25
this("","","",5); ?*tb|AL(R
} u0Fu_Rtr
pBG(%3PpW
`sAz1/N
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) x%jJvwb^|
{ _}vD?/$L
sSiteURL= sURL; FQ*4?D,A
sFilePath = sPath; 9P#E^;L
sFileName = sName; |nk&ir6
this.nSplitter = nSpiltter; W8'cAY
qHt!)j9GKv
A<C`JN}
} :lcZ)6&S
g PU|Gv5
&s>HiL>f
public String getSSiteURL() 1l"A7 V
{ zC\ pd#
return sSiteURL; pE[ul
} Q?B5@J
)F,H(LblH
jV;&*4if
public void setSSiteURL(String value) zZ3,e L
{ <iajtq<Z
sSiteURL = value; ek1YaE
} q.`+d[Q2
z)='MKrEt-
Ix93/FAn
public String getSFilePath() qrsPY d
{ BQ2EDy=}6
return sFilePath; <]r.wn=}M
} cor?#
x JQde4
}eXzs_
public void setSFilePath(String value) =toqEm~
{ j{?,nJdQ
sFilePath = value; 2$. ubA
} Xm8 1axyf
q g?q|W
kL 6f^MoL
public String getSFileName() RMMx6L|-:
{ a)$"
return sFileName; ?%J{1+hY
} -ve{O-;
rhO ]4A
AB'q!7NR
public void setSFileName(String value) O4ciD1
{ qba<$
sFileName = value; T]l_B2.
} yd2v_
3/RmJ`c{
;aExEgTq
public int getNSplitter() wXIsc;
{ 6TvlK*<r=
return nSplitter; e;5n.+m
} M:z)uLDw
aT$q1!U`j2
@C{IgV
public void setNSplitter(int nCount) X3vTyIsn
{ D *RF._
nSplitter = nCount; b*S:wfw
} ER~m &JI
} 4J Bm|Pf(
>Ip>x!wi
Qctm"g|
/* {y0#(8-&
**Utility.java p:U9#(v)
*/ =PWh,lWS
package NetFox; Z;M]^?
/.l8Jb4
O'{UAb+-
public class Utility { R| [mp%Q
Y[k%<f
4vq,W_n.hQ
public Utility() xwhH_[
{ 2qLRcA=R
SV}q8z\
p(in.Xz
} >H?l[*9
9=7),`$
//线程睡眠 rT9<_<
public static void sleep(int nSecond) uUu]JDdz
{ ?W-J2tgss{
try{ [0U!Y/?6lA
Thread.sleep(nSecond); ;A7HEx
} Ymkk"y.w
catch(Exception e) - ?_aYJ
{ xjB2?:/2
e.printStackTrace (); [ &RZ&
} ESp)%
} /_}xTP"9
GzxtC&
//日志 [ R1S+i
public static void log(String sMsg) -fIX6
{ t"k6wv;Tq
System.err.println(sMsg); Fn.wd`'0
} F#>?i}
ig:,:KN
A ^@:Ps
public static void log(int sMsg) nQ2V
{ k_?xiOSh
System.err.println(sMsg); ikf!7-,
} W8+Daw1Nr
} ,=whwl "tA
fYU/Jn#
,Q!sns[T
/* k0~mK7k
**TestMethod.java &0Yv*,4]
*/ U\'.rT[#
package NetFox; NKf][!bi
6KC.l}Y*
a<9gD,]P
public class TestMethod { |Z'NMJU
HTiqErD2_
|!:ImX@
public TestMethod() tn!z^W
{ ///xx/weblogic60b2_win.exe gBfYm
try{ ZLw7-H6Fh
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); f(~xdR))eh
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); M7!>-P
SiteFileFetch fileFetch = new SiteFileFetch(bean); |:Gz9u+
fileFetch.start(); Hf!o6 o
} yk OJhd3
catch(Exception e){e.printStackTrace ();} OEmz`JJ67
J4 [7*v
UUi@ U
} GADbXp3
\o3)\ e]o
Nr)v!z~y
public static void main(String[] args) ][3H6T!ckL
{ pwAawm
new TestMethod(); SQx%CcW9d
} spter35b[
} QSPneYD
点击下载更多相关资料