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)); It]GlxMX
} JH#p;7;
for(int i=0;i<nEndPos.length-1;i++) ^}UFtL i
{ I0N~>SpZ5
nEndPos = nStartPos[i+1]; iGBHlw;A
} CropHB/t
nEndPos[nEndPos.length-1] = nFileLength; ^[6#Kw&E
} (ylZ[M&B:
} iM$iZ;Tp
+fHqGZ]
4YXp,U
//启动子线程 mln%Rd6u/
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; 4m%Yck{R
for(int i=0;i<nStartPos.length;i++) s6DPb_,
{ 9fYof
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), +1K=]#a
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), !FQS9SoO9
nStartPos,nEndPos,i); O' Mma5
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); @P">4xVX{
fileSplitterFetch.start(); M 9 N'Hk=
} EL6<%~,V"I
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), _`Dz%(c
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); \SBAk h
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", vvLzUxV
nEndPos = " + nFileLength); `ghNS
// fileSplitterFetch[nPos.length-1].start(); !>WW(n07Ma
H{uR+&<
,nWZJ&B
//等待子线程结束 of'H]IZ
//int count = 0; U%KgLg#
//是否结束while循环 [4-u{Tu
boolean breakWhile = false; JmuoYlf|
g@m__
@2eH;?uO
while(!bStop) +D?Re%HI
{ 6?-,@e
write_nPos(); `a8&7J(
Utility.sleep(500); 91ec^g
breakWhile = true; y(j vl|z[
i x_a
jF{)2|5
for(int i=0;i<nStartPos.length;i++) _@Y17L.
{ LbnF8tj}h
if(!fileSplitterFetch.bDownOver) fK{Z{)D
{ ^AT#A<{1(
breakWhile = false; nIl<2H]F`
break; m@yx6[E#
} {sUc2vR
} Bm;@}Ly=G
if(breakWhile) ):V)Hrq?x
break; P9]95.j
XeXK~
!/Wv\qm
//count++; CYNpbv
//if(count>4) ?xt${?KP
// siteStop(); _mDvRFq
} R/&C}6Gn
}S9uh-j6l
h=_h,?_
System.err.println("文件下载结束！"); _2eL3xXha.
} !<^`Sx/+
catch(Exception e){e.printStackTrace ();} PU%WpI.w
} CM+wkU ?,
BgwZZ<B
pXe]hnY
//获得文件长度 *4 Kc "M
public long getFileSize() QezDm^<
{ !e0/1 j=
int nFileLength = -1; L/:u
try{ 7P DD
URL url = new URL(siteInfoBean.getSSiteURL()); ^j'vM\^`ml
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); ntF#x.1Pm
httpConnection.setRequestProperty("User-Agent","NetFox"); 0.!Q4bhD
5O"wPsl
q?oJ=]m"
int responseCode=httpConnection.getResponseCode(); 7 P]Sc
if(responseCode>=400) +e)RT<
{ dYhLk2
processErrorCode(responseCode); mWU*}-M
return -2; //-2 represent access is error 0Y\7A
} =Y5*J#
.w)T2(
1;9 %L@
String sHeader; CYC6:g|)
Oxf,2r
h_h6@/1l
for(int i=1;;i++) 0"M0tA#
{ e7gWz~
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); b"z9Dpv
//Utility.log(in.readLine()); %suXp,j
sHeader=httpConnection.getHeaderFieldKey(i); .g6(07TyV
if(sHeader!=null) Ps{}SZn
{ N+NS\Y5
if(sHeader.equals("Content-Length")) %i`YJ
{ kx3]A"]>'
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); f%Bmx{Ttq
break; Hy1f,D
} ACxjY2
} \6v*c;ZF
else PRF^<%mkI
break; ~TALpd
} "G!V?~;
} :#p!&Fi
catch(IOException e){e.printStackTrace ();} tL@m5M%:N2
catch(Exception e){e.printStackTrace ();} N @sVA%L.
-%)8=
$kk!NAW
Utility.log(nFileLength); W>]=0u4
`'<&<P
(6\ H~
return nFileLength; |/AY!Y3
} }[I|oV5*+&
Mkadl<
& pS5_x
//保存下载信息（文件指针位置） {!vz 6QDS
private void write_nPos() w`OHNwXh#I
{ oGi{d5
try{ cX/["AM
output = new DataOutputStream(new FileOutputStream(tmpFile)); kP}91kja
output.writeInt(nStartPos.length); [8.w2\<?
for(int i=0;i<nStartPos.length;i++) &\o!-EIK8
{ awa$o
// output.writeLong(nPos); >P\/\xL=
output.writeLong(fileSplitterFetch.nStartPos); ZN?UkFnE
output.writeLong(fileSplitterFetch.nEndPos); ;}gS8I|
} tvG/oe .1'
output.close(); FqK2[]8
} ZX!u\O|w
catch(IOException e){e.printStackTrace ();} />9?/&N6"
catch(Exception e){e.printStackTrace ();} (Dx]!FFz
} y|@=j~}Zq
k"2xyzt*
*QpKeI
//读取保存的下载信息（文件指针位置） I|?Z.!I|
private void read_nPos() 675x/0}GO
{ FucLcq2Z
try{ hkL[hD
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); 8TnByKZz
int nCount = input.readInt(); ~V4&l3o
nStartPos = new long[nCount]; y(RK|r
nEndPos = new long[nCount]; Ka\%kB>*`
for(int i=0;i<nStartPos.length;i++) SggS8$a`
{ fX2PteA0qX
nStartPos = input.readLong(); S?_ ;$Cn
nEndPos = input.readLong(); 3QrYH @7zx
} pJE317 p'
input.close(); U ]6Hml;l
} yegTKoY
catch(IOException e){e.printStackTrace ();} B[0XzV]Z
catch(Exception e){e.printStackTrace ();} %%w]-`^h,
} 3q.O^`y FU
xFY;aK
v+|N7
private void processErrorCode(int nErrorCode) nUvxO `2
{ b%<i&YY#
System.err.println("Error Code : " + nErrorCode); (U |[C*
} UC34AKm
Py8<db%
|0mVK`
//停止文件下载 3J{`]v5`
public void siteStop() BZE~k?*
{ /IC7q?avQN
bStop = true; l&4TfzkY
for(int i=0;i<nStartPos.length;i++) rE bC_<
fileSplitterFetch.splitterStop(); @M-+-6+
2|)3Ly9
~a5p_xP
} [EJ[Gg0m
} Kj_hCSvf3e
//负责部分文件的抓取 _azg 0.)
**FileSplitterFetch.java l*]*.?m/5
*/ e/m,PE
package NetFox; DT@6Q.
\@4_l?M
5"5D(
import java.io.*; 8uX1('+T*
import java.net.*; B;?"R
(Ia}]q
iG*/m><-
public class FileSplitterFetch extends Thread { r c7"sIkV
qlSc[nEk
DH_Mll>
String sURL; //File URL @l^=&53T
long nStartPos; //File Snippet Start Position u5EHzoq
long nEndPos; //File Snippet End Position 2Ek6YNx
int nThreadID; //Thread's ID 2hRaYX,g
boolean bDownOver = false; //Downing is over EIwTx:{F
boolean bStop = false; //Stop identical V>j6Juh
FileAccessI fileAccessI = null; //File Access interface lV-7bZ
)dJaF#6j
RvYH(!pQ
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException # a 'h,
{ 9psX"*s
this.sURL = sURL; '@u/] ra:
this.nStartPos = nStart; 9(Vq@.;Z`j
this.nEndPos = nEnd; /}Y>_87
nThreadID = id; [BHf>
fileAccessI = new FileAccessI(sName,nStartPos);//定位 Mrp'wF D
} 8Z!+1b
k|,pj^
2@o_7w98
public void run() FG-w7a2mn
{ Nf>1`eP
while(nStartPos < nEndPos && !bStop) 02} &h
{ +n]U3b
]S[zD|U%
#{GUu',?&
try{ n< [np;\
URL url = new URL(sURL); %,GY&hTw
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); SU9#Y|I
httpConnection.setRequestProperty("User-Agent","NetFox"); Pn5@7~
String sProperty = "bytes="+nStartPos+"-"; lC+p2OG^[
httpConnection.setRequestProperty("RANGE",sProperty); tgDmHxB]0
Utility.log(sProperty); 9/RbfV[)
SM5i3EcFYP
UcDJ%vI
InputStream input = httpConnection.getInputStream(); [K[tL|EK
//logResponseHead(httpConnection); _`L,}=um'
4em7PmT
vfJ}t#%UH
byte[] b = new byte[1024]; pFGK-J
int nRead; k'wF+>
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) LQ?J r>4
{ 3KfZI&g
nStartPos += fileAccessI.write(b,0,nRead); _$By c(.c
//if(nThreadID == 1) Wy,DA^\ef
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); rB}UFS)
} V{fYMgv
BUv;BzyV
3Qe:d_
Utility.log("Thread " + nThreadID + " is over!"); >/EmC3?b!
bDownOver = true; _h7+.U=
//nPos = fileAccessI.write (b,0,nRead); dZRz'd
} f 5_n2
catch(Exception e){e.printStackTrace ();} L._I"g5 H9
} Nm#VA.~
} $g _h9L
AL}c-#GG
Xd66"k\b+
//打印回应的头信息 e%j+,)Ry
public void logResponseHead(HttpURLConnection con) .5dZaI)
{ H<NYm#a"
for(int i=1;;i++) 3}h&/KN{
{ ;^rZ"2U l
String header=con.getHeaderFieldKey(i); BV!Kiw
if(header!=null) sL\|y38'
//responseHeaders.put(header,httpConnection.getHeaderField(header)); }VFSF/\^
Utility.log(header+" : "+con.getHeaderField(header)); ^ g4)aaBZ
else Y^6=_^
break; DG:=E/@
} VS}Vl
} gf3/kll9
u{3KV6MS
:ZzG5[o3
public void splitterStop() ar^`r!ABEh
{ 9Q.j <
bStop = true; lhjPS!A~
} I9u=RIs
#|e<l1F
}>OE"#si
} J`x9XWYw
R-h7c!ko
aSK$#Xeu
/* my} P\r.
**FileAccess.java -[7.VP
*//文件访问(定位，写) "Km`B1f`
package NetFox; 1u`Z?S(
import java.io.*; 2xnOWW
UG!&n@R
9rid98~d
public class FileAccessI implements Serializable{ qMUqd}=P
|/(5GX,X
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 h]=chz
RandomAccessFile oSavedFile; P#0_
long nPos; {otvJ|'N
MUo?ajbqOd
}.hBmhnZmI
public FileAccessI() throws IOException O@$hG8:
{ K:Ap|F
this("",0); 2cDC6rul
} _9-Ajv
"d#s|_n,d)
'0=U+Egp
public FileAccessI(String sName,long nPos) throws IOException cK258mY
{ $K iMu
oSavedFile = new RandomAccessFile(sName,"rw"); ?y '.sQ
this.nPos = nPos; 6JL 7ut
oSavedFile.seek(nPos); dqe_&C@*O
} =?2y <B
pQ/:*cd+M
L"Gi~:z
public synchronized int write(byte[] b,int nStart,int nLen) F;ZLoG*U
{ fg9sZ%67]\
int n = -1; V4"AFArI
try{ lAGxE-B^a"
oSavedFile.write(b,nStart,nLen); :vr,@1c
n = nLen; #[si.rv->
} \?g%>D:O;
catch(IOException e) u1"e+4f
{ L=p.@VSZ
e.printStackTrace (); l&rDa=m.J
} nqH^%/7)A@
u7;A`
?1{`~)"
return n; I*ej_cFQ^
} %,^7J;
|Bn=$T]
^4[\-L8Lpq
} }}2kA
aw 7f$Fqk
j@ "`!uPz
/* ^DH*@M
**SiteInfoBean.java x B?:G
*/ B -KOf
package NetFox; ky#6M? \
K c<z;
w0IB8GdF
public class SiteInfoBean { `%Ghtm*
^Pf&C0xXv
gv,T<A?Z2
private String sSiteURL; //Site's URL E,|n'
private String sFilePath; //Saved File's Path \XN5))
private String sFileName; //Saved File's Name 5u;Rr 1D
private int nSplitter; //Count of Splited Downloading File 7P/?wv9+n*
x|@1wQ"6
I&TTr7
public SiteInfoBean() Gur8.A;Y
{//nSplitter的缺省值为5 z(g%ue\
//default value of nSplitter is 5 :DtZ8$I`]C
this("","","",5); /h}PEu3y
} MxO W)$f
.'t (-eT,
FOOQ'o[}
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) IL~]m?'V(
{ )XLj[6j0
sSiteURL= sURL; 2d-TU_JqX
sFilePath = sPath; 9W{,=.%MX$
sFileName = sName; 6gj]y^}
this.nSplitter = nSpiltter; {0is wq'J
j0g5<M
:3f-9aRC!
} F(Lb8\to\M
R%>jJ[4\[
_1I K$gb[
public String getSSiteURL() h&)fu{
{ :PgF
return sSiteURL; z-n>9
} uQH%.A
=WIE>*3[
/8f>':zUb
public void setSSiteURL(String value) }5Yj
{ ,"~WkLI~\t
sSiteURL = value; 'S =sj}X
} `_|aeoK_
:1:3Svb<Y
%dEB/[
public String getSFilePath() hT?6sWa
{ 10mK}HT>4B
return sFilePath; ov8 ByJc
} dVa!.q_3
F"!agc2!
+wipfL~&S
public void setSFilePath(String value) FC6xFg^
{ e|yX QTlvL
sFilePath = value; }*NF&PD5RU
} BWWq4mdb{
fV 3r|Bp
`)T&~2n
public String getSFileName() 1@xP(XS
{ )B6# A0
return sFileName; 2gt+l?O<PS
} hi!`9k
c7\VTYT
+=7:4LFOL
public void setSFileName(String value) cph~4wCS[U
{ tR1FO%nC
sFileName = value; WSRy%#
} C}q>YRubZ
ld.7`)
r4u z} jl{
public int getNSplitter() r$ =qQ7^#
{ b^x07lO
return nSplitter; #Q}_e7t
} Z0-ytODII
Ql8bt77eI-
L;S}s, 2x
public void setNSplitter(int nCount) ?Nf 5w
{ bHE7yv [
nSplitter = nCount; Z, T#,
} KVN"XqE4
} Q8q@Y R#
4/'N|c.
sHdp
/* EiWd+v,QJQ
**Utility.java Lu=O+{*8
*/ z\TLsx
package NetFox; &$=!dA
_7"5wB?|+
'H|~u&?
public class Utility { NLyXBV[hV
e4\dpvL
ZSB?Y1wG
public Utility() Y.sz|u 1
{ w2dcH4&
j+kC-U;
Q9c)k{QZ
} bMm3F%FFq&
.TpsJXF
//线程睡眠 %d2!\x%bG
public static void sleep(int nSecond) })Yv9],6
{ QA?oJ_}y
try{ *jITOR!uF`
Thread.sleep(nSecond); D#Kuo$
} n?xTkkr0
catch(Exception e) 8 lT{1ro
{ tg\|?
e.printStackTrace (); )8,|-o=
} )OP){/
} Kz?#C
@Jn!0Y1_3
//日志 =qu(~]2(
public static void log(String sMsg) $B(kZ
{ {tiKH=&J
System.err.println(sMsg); -_N)E ))G
} k N7Bd}
WsGths+[
|~0UM$OB^3
public static void log(int sMsg) 9902+pW
{ eiVC"0-c}
System.err.println(sMsg); <vV_%uoM
} Ib=x~za@n
} ]?+{aS-]?k
9+=gke
p@ NaD=9
/* ?)D^~/ A
**TestMethod.java Lgk
*/ 4rg2y]
package NetFox; yx38g ca
SmwQET<H
p>w]rE:}
public class TestMethod { V)ig)(CT
GL$De,V
saf&dd
public TestMethod() q*7<)VwI
{ ///xx/weblogic60b2_win.exe ^x>Qf(b
try{ )kXhtjOl|
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); tBbOY}.VD
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); rwLAW"0Qz
SiteFileFetch fileFetch = new SiteFileFetch(bean); \y`+B*\i
fileFetch.start(); :Qt
} ElhRF{R
catch(Exception e){e.printStackTrace ();} {76c%<`WaP
dO> VwP
GzXUU@p
} #G" xNl
~}EMk3
GPz(j'jU
public static void main(String[] args) P262Q&.}d
{ tGvG
new TestMethod(); _|[UI.a
} 58\&/lYW
} &s Pq<lo
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