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)); a<o0B{7{BM
} FN,uD:a
for(int i=0;i<nEndPos.length-1;i++) qt:->yiq+
{ .N'UnKz
nEndPos = nStartPos[i+1]; 3)-#yOr
} )xK!i.
nEndPos[nEndPos.length-1] = nFileLength; 2 sOc]L:9
} C {,d4KG
} j?mJ1J5
f7W=x6Z4
y(S0 2v>l
//启动子线程 aLq;a
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; 0jzA\$oD
for(int i=0;i<nStartPos.length;i++) 'H9~rq7
{ 5;Z~+$1
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), $_ i41f[
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), lz*2wGI9
nStartPos,nEndPos,i); n$?oZ*;
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); JQ1VCG
fileSplitterFetch.start(); ;8v5 qz
} {Eb6.
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), Cn<kl^!Q-
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); -s1VlS/
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", GGuLxc?(
nEndPos = " + nFileLength); z[rB/|2
// fileSplitterFetch[nPos.length-1].start(); W9D)QIqbvW
\wCL)t.cX
4<Y?#bm'
//等待子线程结束 [KKoEZ
//int count = 0; QezK&iJg
//是否结束while循环 :Rn9rdX
boolean breakWhile = false; Cf N; `
F)IP~BE-k
G~]BC#nB_
while(!bStop) |eqDT,4
{ ~h/U ;Da
write_nPos(); !v`=EF.
Utility.sleep(500); o(zg_!P
breakWhile = true; 8HOmWQS
]5\vYk
h CiblM
for(int i=0;i<nStartPos.length;i++) GND[f}
{ 6uyf
if(!fileSplitterFetch.bDownOver) qSd $$L^
{ U&XoT-p$L
breakWhile = false; 4HJrR^
break; 'FhnSNT(4=
} &M!:,B
} c>SeOnf
if(breakWhile) 8{YxUD
break; nGVqVSxKT
#L)rz u
bqO"k t
//count++; &}cie"\L
//if(count>4) -ZB"Yg$l
// siteStop(); F*4+7$E0B
} B(falmXJ
v`&Z.9!Tz^
)R4<* /C:w
System.err.println("文件下载结束！"); ]`prDw'
} [XXN0+ /
catch(Exception e){e.printStackTrace ();} @2gMtf?<
} .IXwa,
g8Z14'Ke
sFQ|lU"n
//获得文件长度 K^Ht$04
public long getFileSize() Ie"R,,c
{ ={^#E?
int nFileLength = -1; 2XHk}M|
try{ S2)S/ nf
URL url = new URL(siteInfoBean.getSSiteURL()); ,k!a3"4+TJ
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); &}O!l'
httpConnection.setRequestProperty("User-Agent","NetFox"); {rZ"cUm
(Y([^N q
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int responseCode=httpConnection.getResponseCode(); wY#mL1dF
if(responseCode>=400) l'QR2r7&.
{ d]EvC>
processErrorCode(responseCode); w>uZ$/
return -2; //-2 represent access is error R6;>RRU_
} B! V{.p
}=a4uCE
fP58$pwu
String sHeader; -(1\`g07
jm\#($gl=
I0K!Kcu5Iu
for(int i=1;;i++) )\vHIXnfJ1
{ BA,6f?ktXS
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); p'~5[JR:
//Utility.log(in.readLine()); G:`Jrh
sHeader=httpConnection.getHeaderFieldKey(i); c^s>
if(sHeader!=null) \F~Cbj+'Nu
{ r%d11[z
if(sHeader.equals("Content-Length")) Q/)ok$A&
{ +E|ouFI
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); KVxb"|[
break; e"#D){k#
} ; ,jLtl
} 8"mW!M
else aG_ON0g
break; !m(L0YH
} x9l0UD*+g
} @T1+b"TC
catch(IOException e){e.printStackTrace ();} +wozjjc
catch(Exception e){e.printStackTrace ();} ?i2Wst
siYRRr
(M,VwwN
Utility.log(nFileLength); ih |Ky+!
aGb. Lh9
Xj~EVD
return nFileLength; f~nt!$
} 2BX GVo
,Bw)n,
8`2<g0V2
//保存下载信息（文件指针位置） qlITQKGG
private void write_nPos() nDB 2>J
{ P3tG#cJ
try{ "%''k~UD4
output = new DataOutputStream(new FileOutputStream(tmpFile)); ;'QY<,p[e
output.writeInt(nStartPos.length); ywynx<Wg
for(int i=0;i<nStartPos.length;i++) igBrmaY'
{ dP7Vsa+
// output.writeLong(nPos); #z!Hb&Qi\
output.writeLong(fileSplitterFetch.nStartPos); U?mf^'RE
output.writeLong(fileSplitterFetch.nEndPos); $KWYe{#
} D`:d'ow~KQ
output.close(); 76A>^Bs\/
} ()M@3={R
catch(IOException e){e.printStackTrace ();} '&:1?i)
catch(Exception e){e.printStackTrace ();} @ Rx6 >52>
} FaE#\Q
M*|VLOo=v
$dh4T";
//读取保存的下载信息（文件指针位置） $@_t5?n``F
private void read_nPos() 0w(T^GhZ
{ \DU^idp#
try{ "WbVCT'i
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); Kka8cG
int nCount = input.readInt(); @>fO;*
nStartPos = new long[nCount]; a=*ALd_&0
nEndPos = new long[nCount]; p/k<wCm6
for(int i=0;i<nStartPos.length;i++) 6L,lq;
{ /pN'K5@
nStartPos = input.readLong(); jc&/}o$K
nEndPos = input.readLong(); q)V1{B@
} QGr\I/Y
input.close(); 8VuZ,!WH#
} >bA$SN
catch(IOException e){e.printStackTrace ();} b-BM"~N'
catch(Exception e){e.printStackTrace ();} _+\:OB[Y
} i#RElH
O}MZ-/z=o~
~mK-8U4>K,
private void processErrorCode(int nErrorCode) k%]DT.cE
{ Du^x=;
System.err.println("Error Code : " + nErrorCode); n</k/Mk}
} ) \-96 xd
ZD)0P=%
#7]o6
//停止文件下载 ,v*p
public void siteStop() 4`8IFK
{ M'umoZmW0
bStop = true; lk_s!<ni
for(int i=0;i<nStartPos.length;i++) uNe}"hs
fileSplitterFetch.splitterStop(); 7|QGY7Tf
QB/7/PW{H\
_Z+jQFKJ\8
} \E$1lc
} S5~`T7Ra
//负责部分文件的抓取 ua`6M
**FileSplitterFetch.java MSZ!W(7,<
*/ 731h ~x!u
package NetFox; B2~f;zy`
~reQV6oQua
)L |tn
import java.io.*; ;TL(w7vK
import java.net.*; {*QvC g?
,`<^F:xl
>`7OcjLg
public class FileSplitterFetch extends Thread { S3uyn78hI
qyg*n>nt
Fweh =v
String sURL; //File URL ~ HK1X
long nStartPos; //File Snippet Start Position w]};0v&\~s
long nEndPos; //File Snippet End Position #)GW}U]X
int nThreadID; //Thread's ID $sEB'>:
boolean bDownOver = false; //Downing is over ku{XW8
boolean bStop = false; //Stop identical >P<z |8
FileAccessI fileAccessI = null; //File Access interface S dIGU[fm
r\(v+cd
}{ n\tzR
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException LZ~2=Y< U(
{ [ njx7d
this.sURL = sURL; |d $1wr
this.nStartPos = nStart; 3->,So0Y
this.nEndPos = nEnd; F9MR5O"
nThreadID = id; k/G7.)C
fileAccessI = new FileAccessI(sName,nStartPos);//定位 FZiZg;
} 3brb*gI_b
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public void run() "H>.':c"+3
{ 0$tjNye
while(nStartPos < nEndPos && !bStop) 9C_*3?6
{ \e<mSR
\a"i7Caa
VCjq3/[_
try{ cTM$ZNin
URL url = new URL(sURL); k({2yc#RD&
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); i;c'P}[K
httpConnection.setRequestProperty("User-Agent","NetFox"); - %|P
String sProperty = "bytes="+nStartPos+"-"; q]px(
httpConnection.setRequestProperty("RANGE",sProperty); a mqOxb
Utility.log(sProperty); j'+ELKQ
}'%^jt[3
wa!zv^;N*
InputStream input = httpConnection.getInputStream(); z!$gVWG
//logResponseHead(httpConnection); S?L#N
IAf$]Fh
RU0i#suiz
byte[] b = new byte[1024]; GM](=|F
int nRead; &y70
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) a9=>r
{ *(G&B\
nStartPos += fileAccessI.write(b,0,nRead); CM9XPr
//if(nThreadID == 1) 7rcA[)<'
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); T7{<arL$
} ?q_^Rj$
qe$33f*
zsDocR
Utility.log("Thread " + nThreadID + " is over!"); QdDObqVdy
bDownOver = true; `?|Rc
//nPos = fileAccessI.write (b,0,nRead); :Hk_8J
} O|I+],
catch(Exception e){e.printStackTrace ();} bKMWWJf*'
} f2yq8/J8.
} gfde#T)S
7X}TB\N1
jH>8bXQqZ
//打印回应的头信息 }_}KVI
public void logResponseHead(HttpURLConnection con) l$a?A[M$
{ $W&:(&
for(int i=1;;i++) #op:/j
{ q$gz_nVq,b
String header=con.getHeaderFieldKey(i); -#.< 12M
if(header!=null) S/4r\6
//responseHeaders.put(header,httpConnection.getHeaderField(header)); XWUP=D~
Utility.log(header+" : "+con.getHeaderField(header)); pYo=oI
else M-J<n>hl
break; JJ?I>S N!
} 0C$8g Y*
} 6Ps.E
+;Cr];b3
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public void splitterStop() :et#0!
{ c~imE%
bStop = true; kz B\'m,l
} E]I$}>k
~_>cM c
rrqQCn9
} ObG=>WPJa
>&U@f
oC*=JJe,
/* V`#.7uUP
**FileAccess.java W:`#% :C
*//文件访问(定位，写) y('k`>C
package NetFox; hmC*^"C>U=
import java.io.*; TL0[@rr4
SZhOm
!'G~k+
public class FileAccessI implements Serializable{ ]<XR]FHx)
g(Yb^'X/
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 V'G Ju
RandomAccessFile oSavedFile; Kj3?ve~
long nPos; 9Uf j
i47j lyH
;H'gT+t<c
public FileAccessI() throws IOException H8{ol6wc)6
{ iW%8/$
this("",0); W!T"m)S
} By)u-)g9
h-#1U3d
P7.'kX9
public FileAccessI(String sName,long nPos) throws IOException +B}0=Ex$t
{ o0bM=njok
oSavedFile = new RandomAccessFile(sName,"rw"); T{+Z(L
this.nPos = nPos; bBc[bc>R
oSavedFile.seek(nPos); QDx$==Fo
} XH}'w9VynR
=u[k1s?
2`GOJ,$
public synchronized int write(byte[] b,int nStart,int nLen) %]2,&
{ $za8"T*I
int n = -1; Az;t"
try{ r|u MovnV
oSavedFile.write(b,nStart,nLen); Jl3g{a
n = nLen; iB[~U3
} GfEX>
catch(IOException e) cyyVg!+
{ p Z: F:
e.printStackTrace (); BZ!v%4^9
} #Lv2Zoi>G
u&mS8i}
-i yyn^|
return n; aFz5leD
} jRSUp E8
l vMlL5t
KGH/^!u+R
} W\&8auds
mpPdG
U4aU}1RKz
/* #P l~R
**SiteInfoBean.java N,8/Y
*/ nD5 gP
package NetFox; p$Ox'A4
>Cw<BIF
if|+EN%
public class SiteInfoBean { ks$JP6
s<qe,'Y
#]nx!*JNZ
private String sSiteURL; //Site's URL )OiT{-m
private String sFilePath; //Saved File's Path C{gyj}5
private String sFileName; //Saved File's Name x=ul&|^7D
private int nSplitter; //Count of Splited Downloading File wr[,
R" ;xvo*
Oo"^%F~%
public SiteInfoBean() uwz)($~bp
{//nSplitter的缺省值为5 Vn*tpbz
//default value of nSplitter is 5 oE#d,Z
this("","","",5); rE}%KsZ
} QUu}Xg:
4"gM<z
v?KC%
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) ;\f gF@
{ T:5fc2Ngv
sSiteURL= sURL; { ^cV lC_
sFilePath = sPath; +=O5YR!{
sFileName = sName; tmQH|'>>
this.nSplitter = nSpiltter; 0g0i4IV
xuqv6b.
F(tx)V ~T3
} DRcNdO/1E
Ney/[3 A
C?lcGt!H
public String getSSiteURL() 8_{X1bj
{ V5UF3'3;}
return sSiteURL; a(l29>
} zd@m~V
9I}-[|`u
wK?vPS
public void setSSiteURL(String value) \O2Rhz
{ $<}$DH_Y
sSiteURL = value; IZpP[hov
} XD.)Dl8
C uB`CI
Xu%'Z".>:
public String getSFilePath() <sBbT`
{ 0yD9SJn
return sFilePath; }H^+A77v
} E=nIRG|g
<J)]mh dm
#d6)#:uss
public void setSFilePath(String value) nAv#?1cjz
{ ? m DI#~)
sFilePath = value; 1q7|OWFT
} .+$Q<L
A1O'|7X
M/b Sud?@%
public String getSFileName() 8Vr%n2M
{ 6 (]Dh;gC
return sFileName; l3)}qu
} hgPa6Kd
k>;`FFQU>
ZrpU <
public void setSFileName(String value) *\ R ]NV
{ EJMM9(DQ7
sFileName = value; F3On?x)
} MTuV^0%jD
~%&LTX0s|
,E S0NA
public int getNSplitter() -t!~%_WCv
{ Va"0>KX
return nSplitter; J')o|5S1N
} ag [ZW
)_YX DU
:CG`t?N9M
public void setNSplitter(int nCount) marQNZ
{ p`olCp'
nSplitter = nCount; $V-~Bu-
} 6'k<+IR
} =^M/{51j
DX#Nf""Pw
A8muQuj]~~
/* Ni9/}bb
**Utility.java 9+Np4i@
*/ %~4M+r6T
package NetFox; 0q()|y?}
.s?L^Z^
8W*%aOi5+
public class Utility { ]C!gQq2'a
]E5o1eeg
XWBA^|-N
public Utility() G|bT9f$
{ 0yk]o5a++
@a! #G
xG~P+n7t5$
} $0W|26;
d[iQ`YW5
//线程睡眠 8I=2lK
public static void sleep(int nSecond) `'DmDg
{ 5%Y3 Kwyy
try{ pC#E_*49
Thread.sleep(nSecond); ; 5*&xz
} IPS4C[v
catch(Exception e) Y`~Ut:fZ
{ T^zXt?
e.printStackTrace (); sA+ }TNhq
} (d(CT;
} 1KU! tL
AP3a;4Z#
//日志 LP.]9ut
public static void log(String sMsg) cn3#R.G~
{ fBU`k_
System.err.println(sMsg); `}p0VmD{NE
} {a =#B)6
mVj9,q0
3/P1!:g9
public static void log(int sMsg) 34f?6K1c
{ #$.;'#u'so
System.err.println(sMsg); D,k6$`
} >R'F,
} .#EFLXs
p'Y^X
(^ JI%>
/* M`0V~P`^
**TestMethod.java atj(eg
*/ d9k0F OR1
package NetFox; &5>Kl}7
YX!iL6?~
qv-8)MSr
public class TestMethod { irZ])a
F/]2G^-
M$wC=b
public TestMethod() <;lkUU(WT2
{ ///xx/weblogic60b2_win.exe \UA[
try{ kBS9tKBWg
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); =0 #OU
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); pd?Mf=>#
SiteFileFetch fileFetch = new SiteFileFetch(bean); 59LG{R2
fileFetch.start(); Ao 'l"-
} -uS!\
catch(Exception e){e.printStackTrace ();} 1Yq!~8
`Gs9Xmc|
'B|JAi?
} H8=N@l
GC-5X`Sq
`>o{P/HN
public static void main(String[] args) a .#)G[*
{ Cp\6W[2+B
new TestMethod(); 7g^]:3f!
} /PVk{3
} : 6jbt:
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